RG1 was always intended to last 21 issues (81-100, plus the 80.5 freebie). They've actually added one additional issue, #0, which is coming out in a couple of months and I think tells stories set on Earth during the Autobots' absence.

There're a couple of bigtime doozy moments in the Primus Chamber in the latest ish, including a vision Hot Rod sees that may actually cement G1's place in the weird TF multiverse thingy. And someone else is not dead... but not exactly alive, either, from the looks of it.