It's possible, but I'm not sure how robust it will be. There are a lot of heuristics being used to guess what the options are, if they expect an argument, etc. So when feeding it with a command that was typed by someone, which is most likely correct, it's fairly easy to look up each option in all the possibilities. Not to mention some commands have a very complicated set of rules (e.g. find), and the position of some options is context sensitive, which explainshell isn't (it could be, but that would require a lot of manual work).

It's interesting because I had an idea once to do the opposite: see if explainshell could use completion files from bash/zsh/fish as another source of options besides the man page.