I just checked the TV listing and it appears that virgin are showing the Champions Cup and Europa Cup finals live and free on their showcase channel 100.
I think you'll find both games are on multiple free view channels. Didn't BT Sport release the rights to both games with it being two English teams?
Like I said I'm sure they do this every year. I remember reading BT dont actually make money on having these football rights so letting these big games go out to a wider audience possibly increases sponsorship revenue for them.