During a recent interview, Finn Balor revealed that he pitched moving over to NXT UK towards the end of his recent run in NXT, but WWE opted to move him back to the main roster. 

Speaking with BT Sport, Balor revealed that he pitched becoming part of the NXT UK brand when he felt like his recent run in NXT, which begun in October 2019, was coming to an end:

The idea was obviously shot down, as Finn Balor ended up returning to the main roster on the July 16 episode of SmackDown, the first WWE show back with a full crowd since March 2020. 

Believe it or not, before I returned to SmackDown, I could feel the run in NXT kind of coming to an end and kinda exhausted all of the resources there. I actually pitched the idea of moving to NXT UK, and obviously, that might have been a bold move and maybe a bold pitch.”

Balor also revealed that his appearance in NXT UK in 2019 was not slated to be a one-off, with the Irishman claiming that the plan was to build to a big match with former NXT UK Champion WALTER.

WWE even started building to the match on NXT TV during the first few months of 2020, but the match didn't ever end up happening due to the COVID-19 pandemic:

The surprise appearance at NXT UK about two years ago was something I was really excited about and it wasn’t going to be a one-off, it was going to be more of a regular thing to work towards a match with WALTER. It got taken away from us by the pandemic. It’s still something I am still super invested in

You can watch Finn Balor in action tonight on SmackDown live here in the UK on BT Sport, where Balor challenges Roman Reigns for the Universal Championship.