I think that’s a bad idea.
No. I want to participate in many Japanese only threads. but things could happen. Life calls for example. Other things could be, when I drafted, I was stuck in Japanese grammar I doubted to use, or most probably I haven’t learned the grammar yet, so I put my effort in my draft(s). I use different application(s) for my drafts. Google Keep, Google Docs, Evernote, you name it. I even took about a year just to post one thread.
Although …
Rambling
@Naphthalene 先輩 probably said it better in their own words but let me try to say this in my own words. I hope I can convey what I mean clearly in English. I think it’s more because of my social skills than my language skills. So this is why it really takes efforts for me to talk.Now, now, I want to explain more, but I feel uncomfortable explaining more. So I’ll zip my mouth now. Sorry. I’m even not sure this paragraph is still related to your question, so I just used this details hiding. Anyway. 
Yes, I think you should revive them, but not all if you’re busy. I think WK communities could use this thread to request which thread that needs to be revived because they need to participate.
I think you should remove it completely. One year is ok.
I admire Japanese politeness. Sensei said thank you a lot. Probably if we meet physically you also bow that Japanese bow a lot. Oh sensei. I can’t thank you enough. Thank you. Thank you. Thank you! I’m sorry if I don’t thank you enough!