Or... perhaps absolutely nothing for years!
"Disclosure" is merely some government(s) saying "we've known about their presence for years", while showing sufficient evidence for their existence.
In absolutely no way does it mean that any of the ETs have to make (more) contact with the general public. There's no real reason to think that the status quo won't largely remain in place - especially since we know that, to the gatekeepers of this, they have nothing but contempt for the lower dregs of society (that means you and I).
I suspect that after disclosure, there will be years of politicking... maybe even decades of it. At first, it will simply be "we know they exist, and some have come to Earth - there are a few different species". Later there will be "they have been watching us for a while". Then, later still, "we've been in contact with some of them for a few years, in secret'...
I certainly don't think that those races that have been walking amongst us for years are going to suddenly announce their presence - that would be a massive shock to our psyche, and many wouldn't deal with it well. Paranoia would be rife