I think that's a good idea to give it +50. It's the kind of subtul buff where you can clearly see the consequences ( the ability to 2-hit sera pgen and mexes). It's clear, and doesn't break much balance imo, mostly cause few people will actually make use of that in games (air players in teamgames, high rated player with good knowledge of the game).
Now, does it NEED a buff right now ? I don't know. Yes the unit feels weaker than other bombers, but Aeon is generally considered to have too many good things going for them atm, so idk if the balance team would be able to justify another aeon buff.
Besides, I have the feeling that the value of 3450 damage was exactly set to avoid the Shocker to 2 hit seraphim T3 Mex and Power. I guess that's part of "seraphim have tanky buildings" in general.