I think if we see any legendary pokemon it will be the johto bunch considering they where in the last gen 3 games
I don't see us getting gen 4 Legendary Pokémon due to the fact we got them as events and in game in gen 5 we haven't had a johto event since gen 4 - when johto was out
I think the dogs will roam like the birds in Kalos depending on the starter (like in FRLG)
also your in game character is from johto and we were given johto starters in emerald
I say everything leads to Johto legends
I think the most Johto we will get would be Navel Rock.
Besides, we already had a Johto remake... Those Pokemon need to step aside a bit longer.
This is Hoenn's time to shine.
and not entirely true, we just got Celebi.