Catch 22. If you buy it now, they'll put out a discount next week. If you wait, the price will go up next week.
I will say, you can always upgrade your pass. IE if you buy a 2 park pass and then
Epic passes become available, I'm fairly sure you'd be able to upgrade to include Epic - you can do this right now with Volcano Bay, or to upgrade to a more expensive AP.
Since Disney just increased prices, fair chance that Universal could also. The AP isn't active until you use it, so you're not losing out on anything by buying now and hanging onto it until May. That would protect you from any increases that might happen.
The bigger concern would be if they offer a deal on APs (generally this is a free 3 extra months). Normally you can't apply that deal retroactively. However, I believe if you end up activating the AP while the deal is still valid, you could have them add the deal at the time of activation (if price increased in the interim, you would also have to pay the difference). Pretty sure I read people doing that last year. If they release a deal right after you've bought your AP, you can also call and nicely ask if it can be applied - IME they might refund and allow you to repurchase with the deal - this would require you to have bought direct from Universal and get a nice person on the phone. I did that last year when they did the extra 3 months within a week of me purchasing our APs, but we went on an extra trip specifically because of those extra 3mos so Universal made out pretty good on that.
It really depends on which would irritate you more - waiting and having the price go up, or buying now and missing out on a deal later.
