The reality is that it does not, hasn’t been for years, and won’t any time soon (unless you have a Magical Solution you’re about to implement). In the meantime, this is causing random data loss for users (I’m sure I’m not the only one). It is data loss because once Arc wipes out activity types, and it’s been too long for me to remember what actually happened, that data is now just a best guess and not the actual record of events.
It’s like the problem with Arc recording million segments while stationary due to GPS issues or whatever - in the end, because of the lack of bulk edit option, the user ends up spending inordinate amount of time (hours!) cleaning the timeline. Speaking from personal, excruciating experience I voiced in Dire need for faster edits, which keeps repeating, and there keeps being no option for me to do it faster, due to some vague “there should be a better way” reasoning. But there isn’t!
Not improving a broken UX because of a hypothetical solution that has no timeline is really bad. Like I said, the pain is very real, and the problem keeps repeating on a regular basis.
Please consider this feedback and implement something to make the data safe from random modifications. An explicit button sounds perfect.