Yes, the delays to the project have been well reported - some of it has been Wabtec-Faiveley suffering staffing shortages (which has as widely reported affected their other work too - power door HSTs a notable example) and also underestimating the work involved - particularly with regard to condition of bodyshells, but there are other reasons outside of the manufacturers control as well. All the 769s for Northern and TfW were laid up for nearly a year unable to move on Diesel while the redesigned exhaust system was awaiting emissions testing after the initial/validated design was found to be not in gauge. Production was suspended as there was no point fitting out further sets until that was sorted.
Northern are now in an industrial dispute for their units as well pushing it back for them even further.
It’s very encouraging to see them out and about training today - and the experience gained by TfW will go on to help all the operators planning to introduce them.