My thoughts exactly and whilst there may have been actual technical problems, for them to all suddenly surface after TfL takeover must be a very good coincidence. Either that, or TfL have found problems and want them fixed so in the long term the fleet is more reliable, whilst in the short term it means more delays, short-forms, and cancellations.
Take it from a driver who drives them. There came a point where as a driver writing up fault reports was nothing more than a handwriting practice exercise. All that you would get in reply from fleet was "aware" or "awaiting parts" We had 317s with passenger information un-serviceable or used to announce in reverse for years on end. Trains with dud electronics packs running around, units on half power kept as 8 cars to disguise issues. 315s with faulty TPWS racks defective radios which were left rotting and dispatched onto the Liv St - Shenfields burried in middle cabs for as long as I've been working because nobody wanted to pay for them to be repaired. Then suddenly on the 31st may LOROL are given a small number of these units which all couple and uncouple at some point during the day exposing all of the dark secrets left by AGA. Theres no get out of jail cards no unit swaps and no "burying" of cabs.
So they end up back in ilford because they arent fit for service, getting a thorough looking over ironically enough by GA fitters who will continue to maintain the LOROL/TFL fleet. The difference this time? LOROL are paying for the parts.
Ive driven the same trains for one, nx, ga and now lorol and I can tell you that the units that have emerged after a lorol dressing down are almost like new trains. I know its not much of a consolation to passengers, and shortforms are a pain in the proverbial, but the state they were in underneath was unbelievable, dont be fooled by the GA shiny white repaint with red doors, they may aswell not have bothered.
If they (lorol) continue to service the fleet the way they have been and contiune the internal refreshes the short forms I'm sure will calm down considerably.
My one gripe at the moment though with the short formations is the new line controllers dont appear to be choosing the unit diagrams very well meaning that some of the units are being pulled from extremely busy trains, while other services that are moderately busy are remaining 8cars. Im hoping that in time they will learn how to do things over here, as bad as GA were their line controllers were expert at juggling dead/faulty units around the service and keeping delays down to a minimum and they knew the service very well. Lets hope in time the lorol have that same "cosiness" because at the moment you still get the impression its still a learning curve which is leaving most evening peaks looking a complete shambles.