It looks somewhat intentional if you ask me, since it's not indended to disarm the charges, just disconnect them from the blasting machine (the fuzes are still on the charges).

My suggestion here would be to add an interact option to (re)connect armed charges (back) to your blasting machine. The initial interaction when arming is "arm and connect...", so once it's armed, instead of only being able to disarm and arm again, it would be better to just be able to connect it when the fuze is in it.

It also happens that when all charges get disarmed on by one on site, the detonator still pretends to be connected. Ultimately, it's up to BI to decide what's intentional. I could see though why it could be partially intentional. Could make sense if you are far a way with the detonator and someone else is disarming them. In contrast, it's less sensible if you are the one that disarms them on site, as arming/disarming behavior become inconsistent that way, i.e. arming connects detonator and adds fuze vs disarming only removes the fuze, but leaves the detonator connected.