So after taking some time away to consider some of this, I think that I partially agree with @ganymede. But only partially.
The moving cap idea is okay, if the cap moves fairly often. Capping things 'per season' of something seems like too much of a hard-and-fast cap for my tastes. But I'm also okay with the idea of capping the amount of xp that can be gained per week, or per scene, or whatever. Eldritch currently has that. You can get whatever the auto-gain is, +10 regular beats for doing things, +10 extra beats per player for running things per week. Which ultimately comes out to something like 4-6 xp a week max, which is pretty high under the WoD system, if you're running at full burn and are willing to do enough stuff to hit that number.
As very few people actually hit that number or anywhere close to that number, it doesn't create unreasonable setbacks, while still allowing for some degree of parity.
The amount of xp you've earned in auto-gains also slows down the more xp you have, so the older people have to do more in order to keep their advantage over newer people, which is also kosher with me. New people don't have automatic equal footing with the people who are already there (in which I agree with @Miss-Demeanor, at that point you're really just sticking it to your existing players). They start with the same things in chargen as everyone else started with in chargen, and have to work their way up from there. That's still equality. Not 'gimme all the stuff too' equality, but 'I have a chance to get there as well' equality.
So, in consideration ... personal per-short-period-of-time caps are okay, so long as it's not a game-wide ceiling that isn't gonna move for a good long while, but I still don't buy this 'new people should be able to do all the same things at the same level that existing people can' mentality, or the idea that those who can't for whatever reason do as much as others should be equally 'rewarded'. You get out of it what you put into it.