I mean yes it is marketing and was an attempt to see if something would foster, probably since it fit the theme. It is by definition manipulative.
And it kind of worked! People liked the doing silly memes and such over the weekend and the team for the official english website clearly had some fun writing up goofy articles (the Japanese site lacked most of that, usually opting for social media goofs).
Were that many people doing silly memes? I'm sure there was a few, I know Bulbapedia and Serebii did things, but otherwise I don't recall really anyone else, especially after the first day. And, no, things the Pokemon Company controls don't count. They were trying to do a viral marketing thing which has to be something that's spread by people outside of the owner's of the thing. The official Pokemon website, Youtube Channel, and Social Media Channel aren't part of the viral marketing, they're just part of the normal marketing.
From what I experienced, they did the initial "My Friend Malamar" video of the painter, we talked a bit about it on Smogon, and after that very little. Eventually they released another video with the cabby, I saw one or two references here, of course we had the fansites and official Pokemon store doing a little thing, but that's it until the official reveal.
Anyway, opinion on Mega Malamar:
Design: You know, I think I like it. On paper it sounds rather lazy, but I think they pulled off the effect they wanted with as minimal changes as possible. Malamar is based on a squid (specifically the deep ocean kind which invert themselves and glow, hence its evolution gimmick) with aspects of being a supervillain; Normal Malamar more leans on the squid aspect, so Mega Malamar leans into the supervillain via with the raised pointy shoulders/collar and the "big exposed brain" trope (which leads it to having a more alien design, which you could say fits with it being a deep ocean animal as that's as alien as you can get on Earth). Like many, I immediately thought of two characters: Megamind and the Mars Attack Aliens. Still, while that covered the big brain part, there was something else I felt I was missing. And so, the Lockstin video came out and reminded me what I was thinking of! He pointed out a possibly inspiration from Mindflayers/Illithids and Cthulhu (and that's when I remember... it for some reason reminded me of the Digimon Dragomon; I don't know either). Eitherway, a simple design change that I feel works, like the only thing I would maybe have also done would make the beak longer and bend downwards, sorta like Tentacruel's but not that long.
Lore: But this is where I have to agree with some of the issues that
doipy hooves pointed out, and maybe also why I wasn't clicking with the viral marketing. Nothing really about Malamar's personality or behavior have changed, it just now has stronger psychic powers for what's that worth. Like I would think the next level to Malamar's power would be actually mentally possessing people & Pokemon, literally using them as puppets. OR maybe it would do the opposite of what the campaign suggest it would do, it would manipulate and implant subconscious suggestions into its target and then make you forget about it (aka
the Silents from Dr. Who or a
False Hydra thing). Or, to keep in theme of Mega Evolution being too much power for a Pokemon to contain, Mega Malamar has occasional "brain blasts" that accidentally overwrite nearby people's memories to ones about it which causes them to go crazy (like a
CONTRARY version of themselves) as we saw in the teasers; Malamar wouldn't normally want people to act this way as it's counterproductive to its plan. Malamar would just see its Mega form as a means of raw power and potential mass hypnosis capability, but otherwise it would prefer to stay in its normal form until the right moment to strike.
In-Game Stat Predictions: Quickly talking about Abilities, I guess since nothing about Malamar has really changed there's no reason for it to not have Contrary. Though, it is big brained now, could be given Neuroforce. Psychic Surge (Japanese name "Psycho Maker") could also be a possibility. Then there's a possibility of a new one, maybe one that has to deal with inflicting Sleep more often/better?
I also wonder if maybe there's going to be a new Sleep-inducing Psychic attack? Wouldn't want it to be a Signature Move but also wouldn't be against it if that means its well balanced to be usable but not broken.
As for stats, that's a tough one. Because, remember, Malamar actually leans PHYSICAL. An increase to psychic power would suggest an increase to Special Attack (and a thinner body suggest a decrease in physical strength), which would flip (pun not intended) its role (if so, it would be one of those Mega where you plan on using it as a Mega from the start its moveset wouldn't be compatible between forms). Physical/Special Switch: 86/92/88/68/75/73//482 > 86/72/78/148/85/113//582. Another thing they could do is a mixed set, increase its offense & speed while lowing its defenses to squeeze some extra points: 86/92/88/68/75/73//482 > 86/122/68/128/65/113//582.