This time it was just me.* I do not always react immediately to messages.
Is it scary or weird? Well, in this case i think not because that was somehow the purpose of re-using that unique username. Answered your DM.
edit: Thanks for reminding me to be cautious, though. I've had my share of dominant-competitive idiots to cope with lately, and a very new account DMing me could of course also be someone coming back at me. ... OTOH, could also totally be like me legitimately interested in a specific thing and wanting to get in touch with someone for real. :-) Kind of an approach one would do on Kbin/Mastodon/Twitter. And i don't really look into my Reddit messages anymore.
(*) Other times, it was impossible to answer to comments from Kbin. There was some technical issue and idk if that has been resolved.