I'm unable to speculate whether the Tudor GMT price will increase to the extent of what Rolex is presently undergoing. From what I gather gleaming from web sources, the present mind-boggling situation with regards to the prices of Rolex professional stainless steel range in the grey market, and almost non-availability in MRSP is due to a multitude of factors. Whether similar factors will exist in Tudor's context remain to be seen.
I was interested in the BLRO, but given the fact that stainless steel Rolex GMT is almost impossible to get in MRSP, I'm now seriously considering the Tudor GMT on its own merits - it's a beautiful and practical watch. I personally believe the Tudor GMT offers a lot of watch at that price point (at MRSP of course), and my interest in the watch is base on this rather than 'investing' in the piece in anticipation of potential price increase.
However, I'm delaying acquisition of the Tudor GMT until the issue with its date change is confirmed resolved.