I mean, IF THE CABLE WAS PRACTICAL, it could make a lot of sense. It's a two-way street; the UK (and the European network to which the UK is somewhat interconnected) also has lots of renewables, and of course the sun comes out at different times in both places. As mentioned in the article, the UK also tends to overproduce wind power at night. The framing that it's Canada supplying the UK in the article is overly simplistic/wrong; it'd be mutual supply.

However I have some difficulty believing an interconnector that long is really practical. The longest one in the world currently is only 750km (https://en.wikipedia.org/wiki/Viking_Link).