While I think it's not coming any time soon*, Canada's current economic alignment with the US makes them sufficiently far from being a sensible EU candidate that the UK rejoining is still in many senses closer.

Not close, neither is in the foreseeable future, though the future is exceptionally foggy right now.

* at a minimum, I'd expect a reversal of Brexit needing both that polls show at least 2:1 in favour sustained for a year, and also that anti-EU parties like Reform weren't one of the top two polling parties

I think the one scenario that could work for Brejoin is if Labour rebranded itself as the rejoin party to stave off the threat from the Greens.

The Remain contingent is lost anyways. The other side of the electorate is turned off by their waffling. This would give them a cause to rally around and allow them to consolidate their electorate again.

With enough Brexit voters now either dead (they skewed old!) or having changed their mind, plus younger folks that weren't eligible to vote back then being very pro-EU, that might just do it.