That's for Monolith Soft to do :P

Already been stated in the thread no Monolith is not able to. They have gone on record about it. It's a big job and it was either pot that or make a new game. They could not do both. They need a support studio to port it.

I doubt a support studio with no internal knowledge of Monolith Soft's engine can simply do a port of a WiiU game to the newest version of the engine Monolith used for Xenoblade 3 or their next game, depending if they're gonna make important changes to it again considering the upcoming new generation.

Seems to me the kind of project that can only be done with the people in the know, mainly their core teams.

Anywoo, the interview you speak is now from good time back, decisions like these can change. They finished the trilogy they wanted to. If it comes to a choice between another new game and the remaster/remake of Xenoblade X, it ultimately could land in X's favor considering this is the beginning of a new generation and starting with a re-built "spin-off" wouldn't be a bad choice considering this could lead into the construct of a sequel following it's release.

Xenoblade 3D for the NEW 3DS was ported by Monster Games. But going from an old engine to the new engine would certainly be a huge undertaking. Don't know if Monster Games ported there engine to New 3DS or if it was already there for use.

Ultimately I think X will only get revived if they plan to carry on its story, which i hope they don't. The mainline games have been so much better.

They effectively had to port it to their own engine and test the game thoroughly in all areas because the game was struggling to run the bigger detailed areas of the game (Mechonis Capital Algathara, for example).

Considering this was quite the intensive job for what was also ultimately a 3DS game, I wouldn't want to imagine the undertaking of doing such a project on console knowdays. Monolith have already stated the game would basically have to recoded again since their disparities in their old engine to what they have now. That and the fact the old game was also basically done and tuned on the WiiU architecture and it's features(like the Gamepad).

It's not something I see a small third party porting studio undertaking any day to be frank. 

Anywoo, I wouldn't want simply a port anyway, I'd prefer them to take this opportunity if available, to simply re-built the game to be on parity with the new architecture and also maybe add content into it like they did with XC DE. Hence why I say, only Monolith Soft can touch such a project.