Not sure if anyone got back to you. I am going by planespotters for the sources. The current F-WWTX test reg (as of a Jan 16 photo) is a Frontier A320Neo with a blue jay on the tail, must be one of Frontiers N4##FR series NEOs. No one here has it yet. I de-registered all of the F-WWTX numbers on the list of numbers, but I see the one you are referring to is properly linked to VH-A5B.
Not every F-WWTX reg will show up here if no one shot that particular serial number that wore that reg. I do see that F-WWTX flew on a few A330s and an A340-500 as well.