Clearly, some pokemon are only running certain abilities. Ie, reuniclus seems to only run magic guard, despite also having overcoat and regenerator as possible abilities.
Please show the abilities as well. Thanks.
Abilities aren't setup in the same way as moves are. Each pokemon has a pool of valid moves, hence why we can show that with a command. Abilities however do not have a per-pokemon pool (bar the obvious X pokemon can have X abilities pool, I mean't no smaller randbats ability pool). Instead, we use a script that takes into account several factors starting with the ability's rating, which is an internal rating which basically marks how good an ability is to have in general. You can find ability ratings and details on the ratings here:
https://github.com/smogon/pokemon-showdown/blob/master/data/abilities.ts#L3. You can also find the script I'm talking about here:
https://github.com/smogon/pokemon-showdown/blob/master/data/random-teams.ts#L1855-L1924
Next the script will make a list of the abilities, usually thats going to start with the better ability but RNG is involved so sometimes its not. Next the script tries to pick an ability, when doing this it checks alot of different things, most of which can be found here:
https://github.com/smogon/pokemon-showdown/blob/master/data/random-teams.ts#L1208-L1400 For example, Strong Jaw is rejected if there are no bite moves on the set. If both abilities get rejected, the script randomly picks one.
But even after selecting an ability we aren't done, there are a few final hardcoded choices for special situations such as Copperajah-Gmax always getting Heavy Metal, and various tweaks for doubles formats.
So while some pokemon generally get one ability, more than likely its possible for them to get others. In addition since this isn't a hardcoded list or % chance we can read, its not really easy to add this information to the command. Just assume you could end up with any ability, and if your really curious check to see ability ratings to get a very general and not super accurate idea of which abilities are more commonly picked.