^ Romii only was on the star chart Spock put up on the viewer in "Balance of Terror." The planet was never mentioned in dialogue, and the chart can easily be interpreted as Romii just being another planet in Romulan space.
True, but even when I was a child it looked to me quite obviously like ROMII = Rom. II = Romulus II = Remus.
That is also what I always assumed. Seemed kinda obvious when I first saw it on screen..
What seemed "obvious" to me was that chart that appears to be a star chart (it has little dots of different colours all over the chart, which I interpreted to be stars), and under that interpretation, Romii is in a completely different star system than Romulus, and therefore wouldn't be an alternate name for Remus.
(The whole "simple impulse" can of worms notwithstanding, of course...

)
The big difference is that Enterprise (and Trek) was dead at the time, so nobody really gave a damn. The new movies are ongoing big business, and I can't see TPTB being too happy with their story being rewritten by tie-in fic.
Except we're talking about the distance between Hobus and Romulus - not exactly something that would destroy continuity. TPTB might not care about a detail like that.
I think Hobus was added to the recent
Stellar Cartography book of updated Trek star charts (One Google search later,
HERE it is). The novels tend to keep to what the "nonfiction fiction" Trek books establish (
Federation: 150 Years excepted)
From that map, if we assume a spherical "zone of destruction", then at least Terix, Him(something), Devron, Eden, Romii, and a handful of Earth Outposts would also be destroyed... not to mention any other systems not explicitly called out on the map.
(Granted, if the destruction is more focused along a specific path, similar to a gamma-ray burst or something, then the surrounding systems could end up being fine.)
But you already provided one example where the novels diverge from the reference books... and there are others. So there's really no need for the novels to adhere to the location determined by
Stellar Cartography... just as there is no need for them to even
use the name Hobus, since as has been pointed out earlier, the name itself comes from IDW. All they canonically have to adhere to is "supernova destroys Romulus". Everything else is open to interpretation.
But, sure, they
may indeed end up going with what the other licensees set forth. We'll just have to wait and see...