My question is: can a company create a case where they blame an
employee for follow-up resignations?
It's not at all uncommon for a company to blame current problems on "that guy/gal who used to work here". If it happens, it happens, and there's little you can do about it. So yes, your manager could make a case where they blame you for other resignations.
But, let's be realistic. It's exceedingly unlikely that others are resigning because of you. Almost certainly there have been resignations before you gave yours, and there will be others going forward. One person is seldom the trigger of a mass-exodus, and when it does happen, it's usually a top-level manager, and not a specialist like you.
It's normal that folks are talking to you about their dissatisfaction with the company. They know you are leaving, have probably asked why, and you are probably throwing off vibes.
As to your boss micro-managing you, that too is a natural reaction. In other questions, you indicated your unhappiness for quite a while. I believe you even indicated your desire to leave immediately, without a notice period. Once you gave your notice, it's normal that they would try to manage your remaining time there closely, so as to get what they can get before you check out physically or mentally.
It might feel that way, but this isn't so much about you. Try not to obsess. Just finish out your notice period, leave, and put this company in your past.