I suspect it's more likely than not that the next election will end up getting fought on current boundaries.
The odds are not looking good for getting the current review through Parliament. Even though Conservative MPs are going to like the fact that the new boundaries will favour the Conservatives, many individual MPs will see their seats disappear, which they won't be happy with. Further, this review has particularly onerous requirements for equalizing population between constituencies. While as a principle that sounds like a good thing, it's made it much harder for the boundaries commission to keep communities together, and avoid boundaries running through close communities: That is inevitably going to lead to many more protests about individual new seats than you would normally expect. There's a minor absurdity, that the commission has been legally obliged to keep constituency boundaries aligned with council ward boundaries as they were when the review started - yet some of those boundaries will have already changed before 2020, leading to new mis-alignments. And then of course the real problem - that - as every MP is going to be aware - 10% fewer constituencies will mean 10% more casework for each MP - and many MPs are already completely overloaded with casework.
To get the changes through, somehow, the Government is going to have to sell that to all of it's own MPs AND to the DUP. Personally, I don't rate their chances too highly...