Stat boosts (from levelup) are applied before feat selection, and they DO count towards feats of the same level. Best example I can give is shifter builds that get 30 wis exactly at level 40 and take dragon shape at the same time, which many TC builds rely upon.There are a couple of things like this. It also may be that you have to already have CON of 21 and can't take the EDR in the same leveling turn because you had to already be CON 21 BEFORE the level where you take EDR
The order in which things are applied to a character during levelup: class level, stat pick (not from sources like great dex), skills (includes int levelup), feats. Both stats and skill points are counted towards the pre-reqs for the feats even at the same level. Contrariwise, things you pick at a later stage do NOT count towards the earlier stage. That means if you need 10 tumble to take an SD level, you must have 10 tumble BEFORE you pick your class level (which happens first). So it's impossible to take SD and then get 10 tumble later when selecting skills. Similarly, if you take great int as a general/class feat, it will NOT apply to skill points at the same level, only later.