Do we know how old these Ex Fly Dubai aircraft are ? i presume that they are early models so without the Sky cabin and are they having the Scimitar winglets being added to save on fuel . I just hope for Tui that these replacement aircraft are going to be reliable once the season starts following Covid 19 as the last thing they need is lots of EU261 claims and sub charter costs and extra bed nights.
I know last year when Tui had an Olympus A321 based at BHX go tech for 3 days and they could not get a replacement aircraft it was costing them over 300k a day in EU claims and hotel costs.