One man's bug, is another's swarm of spiders. 😉
OS feature or bug, it would be nice to find a cure. One possible cure would be for new Evernote windows to always appear on top. If that were to happen, I think that the Windows taskbar would not be popping up.
I've followed the threads about this other topic --getting Evernote to open a note on top-- and, this, too seems to be in a state of limbo. For some, notes open on top; for others, including me, notes sometimes open on top (in that case the taskbar doesn't pop up), and sometimes they don't open on top of all other windows.
I oten use another notes program called Notezilla because it mimics post-its and lets me stick notes to my Windows desktop. When I create a note using Notezilla, that note always appears on top of other apps, and never summons the taskbar.