It happened a lot before during ICO hypes.
Offering investors to not sell their coins after listing and then giving rewards to them for just doing it.
The longer you hold it the better rewards they will offer you.
Yeah, it ain't staking.
But, I don't see much of that now. They give bonuses in the start and I don't think they will offer more afterwards.
If we see now indeed most of them will give a large bonus at the beginning and for the end they will not necessarily give a big bonus because we know that new projects now are very difficult to develop because it is difficult to get investors to invest in it and many investors will choose to invest in current top coins so that maybe for new projects or tokens obtained from the project will ultimately have no value.