I never understood this argument to be honest, although it is being constantly brought up. Maybe you could explain the thinking here and the evidence to back it up? My counterarguments are:
1. With new footballing structure on top of manager this decisions will not be up to manager anyway, so the extent of possible clear out should not be that dependent on the manager.
2. Even under “old” structure we had sizeable clear outs in the first few windows under all of LvG, Jose and Ole. There is no evidence that everyone automatically got a chance under new manager. If anything it was often the case that new manager was happy to get rid of previous manager’s signings, like Jose got rid of several of LvG’s signings which would have likely stayed had LvG not been sacked. In this case my guess is that the new manager would be more willing to get rid of the likes of Antony (FFP permitting) then EtH. ETH would likely hold on to him hoping he comes good since if Antony sold at a huge loss - it would make EtH look bad.
3. Yes, you could argue that clear outs were not big enough, but a big clear out of 10+ players is unrealistic anyway, be it under EtH or new manager.
4. The likes of Rashford and Shaw are among our top earners and they signed new contract under EtH so with his blessing. Some of top earners like Casemiro were signed under him. Do you really think he is more likely to push to get rid of them than new manager?
In short, people act as if EtH is some sort of a guarantor of a continued clear out, more so than new footballing people or new manager. I just completely fail to see the evidence/logic behind that