If they were smart they'd do like a reverse Crystal. Have one game include both gens. However start in Kanto with Pikachu, capture the three starters ala Yellow, do that like normal, then go to Johto and start anew there.
Something new yet old at the same time. Then they could jump straight to a Emerald remake, then a Platinum remake. Then a remake called Grey that is sort of the aftermath of B/W2. They could easily do this.
However it wouldn't be done in the span of 1 gen.
Pokemon Black FC: 3653-9864-6035 Pokemon White FC: 4641-8614-2897 (5th Gen Edits only)