That's just not true. You shouldn't take offense to this at all. People have busy schedules.
If I ask someone to coffee and their response is, next month? I’d take it as a clear signal that the content of our conversation or our relationship is not important.
I think it is that “next month” is probably an indication of importance and “next month” will be busy too / the importance of a message you want an AI to spam back… still not important.