The Ben Gorni explains that Eliezer Eved Avrohom went into Gan Eden alive. How is that possible if Avrohom Yitzchok and Yaakov didn’t? He explained that any tzaddik could go into Gan Eden alive since they have sufficient zechusim. The Avos, however, chose to leave over for us zechus Avos so they didn’t have enough to go in alive. Eliezer didn’t care about his eineklach so he kept his zechusim all to himself.
The question then becomes…. what about Moshe? He clearly had enough zechusim to get in alive even after leaving over for us zechus Avos. And that is why the Torah says Kevuraso – it’s a wonderment how he was even buried.