Tough question...
I understand why they want to make changes - it's a bit off balance at the moment and changes are needed to make progression for the game, so I support that.
The concept of how to do that - decrease something, increase something, some combination - I'm not sure what would be the right approach, I am sure there are insane amount of data and simulation capabilities which can give the right answer to the question.
BUT, what I absolutely do not agree with to release something in a rushed pace like this - yeah we will do something in s50, will release it to some games for testing and live from s51 - that's disrespectful to the managers who built teams consciously... at least 1-2 seasons of notice would be expected.
The app question - in my view that's a convenience thing - but a very popular and demanded one from the community for sure.
I think I would do the following:
1. Complete dev for the engine, implement into private leagues and scrimmages for testing - but do not implement in s51, only in s52 or s53.
2. Do the app and release it as soon as you have it ready.
I totally agree with you.
The case you present is exactly mine, and i understand that of hundreds of managers... 9 seasons training my players thoroughly and now that i have to get performance, they change the formula to make external tactics more efficient... these changes should be announced within 3-4 seasons.
I think the change is great and i understand that it is necessary, but obviously it should be announced with much more time so that the teams already formed can change their players with more patience.