Who are the proteges? Well Elizabeth Warren has her own base, which is not due to Bernie. Tulsi maybe?
I don't agree we need new blood, especially as the "new blood" is half the time older than me. Bernie is better than that as he harks back to a more idealistic time, than trust me any Gen Xer does, we're not generally that idealistic a lot, especially as the current crop in politics grew up with tons of money in politics (but if they refuse it, I will note it). Millenials might be different, but they are mostly too young to run (the oldest millenails being like 36 or 37 or something).