I think it depends on how and why a successor becomes leader of the party.
Labour really needed a full electoral cycle to implement the kinds of reforms that needed to come in, and to allow for proper selection of candidates. The former has started to happen at NEC level (notice the difference in how the anti-semitism cases are now being handled), but the snap general election in 2017 scuppered a lot of the latter, and as a result we have a large proportion of the PLP, elected off the back of a manifesto that they would not have written themselves, acting as little more than wreckers with no intention of coming up with policy ideas or engaging the membership.
If the PLP push Corbyn out and try to install their own leader again, then itās very easy to see how they could regain control of the party if there isnāt a unifying single socialist candidate on the ballot.