Deoxys vs Alakazam - comparison
It is probalby going to be a long time since Deoxys is going to be released but I just saw its crazy high attack stat: 345!
Deoxys 345a/115d/100h 2749CP
Alakazam 271a/194d/110h 2887CP
If Deoxys would get the same movepool like Zam, how would it perform in comparison? Since Zam already is a glass canon fainting fast how much faster is Deoxys (not taking it different forms into account) going to faint? Will it be able to deal more damage than Zam?
I know there are lots of variables unclear but this is more a fun question :)
Answers
One of the marketing driven results in all of these kind of games is that the new stuff (whatever it is) has to be a little bit better than the old stuff. If Salamance is just a little worse than Dragonite, people wouldn't bother catching it.
Another consequence of this is that all the effort you put into getting the 'very best possible' mons will be kind of useless after the new mons come out that are a shade better. Kind of like how everyone worked so hard to get Blisseys that could hold down a gym, and then the gym rework happened and defense is not only not meaningful, but can be counterproductive (you don't get paid if no-one takes out your gyms).
So expect there to be some reason for the gym/raid battling players to collect the new mon. A little better, a slightly better move set, or some other tweak. That's the way Niantic keeps players interested in the game going forward - that and changing things up, AKA meta game shifts.
For an answer to your defensive capabilities standpoint, just find a mon with a similar def/hp profile and test at a battle
Easiet I can think of is catch a high level pidgey and use pidgeotto. Then try fighting it with neutral targets or targets it resists. Obviously it doesn't do shit on offense but you can test the longevity.