To answer your last question first, recommendations from current supervisors certainly hold more weight than previous ones (especially if your previous supervisors knew you 4-5 years back and are not in touch with you otherwise - which means they are not aware of your progress or potential NOW). However, this is only if your current supervisor has known you and worked with you closely for a considerable period of time (2-3 years at least). If your current supervisor is not at all aware of your performance before the said two months, then he will surely not have much to talk about you. Take letters from people who have known you for a good duration, in the relatively recent past (2-3 years preferably again), and can talk of such strengths and achievements that would add value to your MBA application and be relevant to your future as well.
As for whether it is advisable to take it from your current supervisor in your present situation, a lot would depend on the kind of rapport you share with him and your understanding of how your request might impact your future prospects. If you decide against this person and can provide a strong reason for it, you might even get the opportunity to explain this in one of your additional essays.
Hope this helps!
Best of luck for admissions!
Manya - The Princeton Review