Unless they completely redesign the Predator itself, or recast Dutch and state he's never seen the Predators before, there is zero difference between a sequel and a remake. Because the whole concept of the Predators has become that they're a race of individualistic hunters, you would have to go a LONG way before any redesign could not be reconciled with the previous films - and I'd argue by that point, it would not really be a Predator anymore.
It's not like there are any recurring characters to worry about
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Most of the Predator spin-off books and comics have had no reference to the original film, and even P2 only referred to it briefly. So a reboot with things that were recognizably Predators, but no direct reference to the previous films, would really be a sequel if you catch my drift. It's not like Batman Begins where you have to forget the previous films for the plot to make sense.
As regards the plot and Rodriguez... I'm getting a serious sense of deja vu. The idea of a group of hunters was in the Thomas' brothers original Predator concept, and was pared down for narrative and budgetary reasons. Rodriguez was supposed to have been nosing around the original AVP script in the early 90s, so again his interest is not surprising.
So, I'll reserve judgement. Mostly what I'd expect is another AVP-R, a decent fun flick with a redesigned Predator that bears no direct link to the original film.