I don't do this every time, but at least once a month; I report this as a problem in the feedback section of teams itself. Sometimes I select give a compliment and then call it a negative compliment. I have a block of standard text that gets pasted in:
Hello there,
Today I received yet another new feature notification from Teams; there is no way to turn these off. This is disruptive to my workflow and pretty arrogant for someone to presume I want to read about new features. I don't care about new features; Teams is forced on me by my IT department; if I had a choice I would use a better group collaboration tool.
Please add an option to permanently display all new feature pop-ups. There is already a little notification icon on the top bar that I cannot delete; use that for these announcements.
Takes next to no time for me to fill out, but someone has to read them. I figure if MS thinks it's okay to waste my time; it must be ok for me waste one of their employees' time too.