Exactly, they'd be RS remakes, but with Emerald stuff mixed in(more likely to have more of an Emerald feel still).
Then it wouldn't be Ruby/Sapphire Remakes. It would be two Emerald Remakes.
From my knowledge,
HeartGold/
SoulSilver have quite a bit of
Crystal-related things jammed into them. On the top of my head, the Suicune subplot and Mysticalman Eusine, Suicune retaining his "roaming Pokemon" moveset from
Crystal, the Global Terminal (which emulates the Pokemon Communication Center that was introduced in
Crystal), animated sprites, the Battle Frontier (roughly an extension of
Crystal's Battle Tower) are all
Crystal elements. HG and SS even have things that the Generation 2 games didn't have
at all (and I don't mean things like 3D graphical enhancements, which was essentially guaranteed by virtue of the DS's capabilities and the standard set by DPPt), such as an event Giovanni battle and walking Pokemon, a feature previously exclusive to
Yellow Version.
The RS remakes are likely going to have
Emerald bits mixed in regardless, such as the Hoenn Battle Frontier, Gym Leader rematches, Pokemon abilities having effects in the overworld (i.e., Flame Body reducing the Egg-hatching duration by 50%), and Speed Forme Deoxys.
Despite these inclusions, the RS remakes are very capable of staying faithful to the original
Ruby and Sapphire Versions while embracing things that made
Emerald great in its own right, just as HG/SS incorporated
Crystal's elements while primarily staying true to
Gold and Silver.
Although my gut is telling me that the
Ruby/Sapphire variant of the "Hoenn" plot will be used, I'd really prefer it if
Emerald's plot was used, as IMO it seamlessly integrates Team Magma and Team Aqua's activities (although Team Magma seems to get a bigger portion of the spotlight...) and give all three members of the Weather Trio a chance to shine. I would hate for Rayquaza to simply be relegated to "that legendary green Pokemon you can catch in that out-of-the-way tower near that out-of-the-way floating city" status, when we
know its connection with Groudon and Kyogre with the release of
Emerald.
Concerning the Battle Tower/Frontier: XanderO, would you honestly have
Ruby/Sapphire's one-mode only Battle Tower featuring only Hoenn-Pokedex Pokemon with subpar items as prizes, or would you rather have
Emerald's full-fledged Battle Frontier, complete with a wide array of move tutors, useful items,
and more than one battling mode (more than one facility, even!) available?
As for which variant of Battle Frontier would likely be used, I would think that the RS remakes would use
Emerald's Battle Frontier setup complete with Hoenn's Frontier Brains, possibly with some revamps. The
Platinum Battle Frontier has been done twice (I thought HG/SS deserved a unique Battle Frontier of their own, but whatever); a return in Hoenn would just seem really lazy, especially since Hoenn has its own Frontier to work off of.
Creating a entirely new Battle Frontier from scratch would just seem very jarring IMO, especially since the Hoenn Frontier Brains are the only "Frontier" group aside from the BW Subway Bosses to have been prominently featured in the anime - they even had a whole
season dedicated to them! Plus, it would just seem rude to do away with what
Emerald managed to contribute to the characters of Pokemon. New Battle Frontier ideas could be quite useful for "
Gray Version", though...