Yeah, but why fix it if it's still a thing in other parts of show. I mean, at the point where Romulans and Suliban use cloaking tech I don't really see the point in retconning the Romulans' cloak into a holo-thing. I'm not opposed to it, personally I think that holo-cloaking sounds kinda cooler than regular cloaking, but the cat is already out of the bag in that case and pushing it back in about halfway doesn't do that much good.
Remember: Star Trek holograms are
weird. They work via forcefields, and they can be created from inside.
So it's entirely plausible (and in fact
logical) to assume both Suliban and Romulans use the same type of cloaking device - a holographic one, that simply makes the ship invisible.
It doesn't make a difference for the Enterprise crew themselves - they still can't detect them without help. But it makes ENT fit with Trek canon as a whole much better: Having a "historic" (22nd century) cloaking device that is basically an invisible field, and a "modern" (23-24th century one) that works by phase-shifting from reality.
It's a bit like the jump from "hull plating" to "shields" - on a narrative level it functions the same. But it still gives a better illusion of technology progressing (the futuristic ones are definitely more advanced), it fixes a whole lot of continuity issues at once (Spock in "Balance of Terror" is amazed to see a ship
vanishing from reality - while historically they just turned
invisible), and generally improves the "shared universe-ness" of Trek.
So really, there is no disadvantage in accepting this little retcon, but a whole lot of improvements on continuity issues. Doesn't mean it
has to be true. But TPTB heavily implied it is, and it makes a lot of sense, and there aren't really any drawbacks. Except maybe for non-canon material like books being affected. Depends on which of those one deems more important.
