Neither of these pokemon are random imo. Ampharos is probably the gen 2 icon, pretty popular, and the mareep line is one of the common cash cows of gen 2. Audino featured in the anime and actually had a decent fanbase in Japan.
You want to give me a good example of random pokemon getting love? Alolan exeggutor. This line has never had revelance in the 20 years of its existance, other than appearing in one or two psychic teams, which still isn't that big, had no merch, and I don't think even gen 1 fans cared much about the guy.
And then it got a regional form, a dragon type, and not only did it get featured a lot more often in places, it's probably remembered much more. Also helps alolan eggxecutor was very memeable due to its size.
Ampharos is a random mon as far as generic fanbase is concerned, which is determined mainly by power.
I wouldn't say Audino fares with the likes of Charizard, Mewtwo or Alakazam, just because it's a remarkable Pokémon in BW that appears in almost every route as a fixed form of grinding exp. Also, Mega-Evolution, which is the thing you are talking about in the first paragraph quoting mine, had a clear interest in bringing back old fans from the franchie appealing to their feelings towards nostalgic mons. And let me tell you, no one gives a shit about Audino in the grand scale of things.
Also, the point of the post wasn't just adressing 2 mons (i mentioned 4 or 5, in fact), but the fact that there are several Pokémon which, while not being necessarily forgotten, they are not the pinacle of the mainstream, and surely less recognizable than things like Dragonite (which is surely, and I mean surely, more iconic than Manectric, having this one received more benefits).
Now, if we are playing the game of no Pokémon that exists is "random" with an argument based on arbitrary criteria, then of course no one is random, since Pokémon is the second best selling franchise in videogame history and mons like Exeggutor are also not random due to their prominency in 1st Gen meta.
Isn't Exeggutor notable as the strong gen 1 grass type that isn't venusaur? It shows up in both the champion and unused Oak fights when that slot isn't used by venusaur (interestingly, the other two variable slots in the champion fight are also two-stage lines, with Arcanine also evolving by stone), as well as the "gen 1 all-stars" part of Greevil's team. Heck, every other grass type in gen 1 caps out at 100 special, 25 points below exeggutor's.
This is exactly what I'm talking about. Random criteria can get you anywhere, and I am able to justify the importance of any Pokémon you can think of basing the argument in everything I know about mons, be it competitive, ingame lore, ingame design (like Audino and their impact in the level curve). The truth is, half of the Pokémon who did receive alternative forms or megas weren't as famous as others who at this point in time havent received anything yet. And compared to those mons, yes, something like Stunfisk, Audino or Ampharos is completely random (like Zoroark or Dnite).
