You can read the source and see exactly what snapd is doing. So, in the sense of knowing what is going on, it’s not at all similar to “Windows update” since I can’t seem to find the source for Windows. 
Or, you know, you could read the documentation and find out that this is configurable. Some configurations are only for v2.58+, but changing the timing has always been an option. By default it’s 4 times a day. You can change it if you wish (snap set refresh system.timer= … with options documented here Managing updates | Snapcraft documentation ). On recent snapd (2.58+), you can even do a “snap refresh --hold” to stop auto-updates and only update manually.
And so I’m not going to install
snapanything on my Librem 14.
Your choice. But since you don’t seem to know some of the control/settings, you might want to read the documentation to make sure your assumptions are correct.
Frankly, I only use snap for things like lxd, chromium and, occasionally, for getting a more recent version of software (e.g. I use the LTS releases for 4 years. There is almost always a feature/fix in ffmpeg that I need. A “snap install ffmpeg” is a lot easier than compiling myself … which is what I used to do.).
I suppose if I were using proprietary software like teamviewer, zoom (like OP), or spotify … I would probably use the snap there too. But I don’t.
For PureOS users, I should note that, presumably, the snap confinement is like it is on Debian. That misses one of the patches that Canonical has not been able to get into kernel.org. Specifically, I don’t think that any of the confinement rules for AF_UNIX (socket IPC) should be counted on. This should not be a huge issue, but people should be aware of it.