Copying images embedded in chat to Outlook 365 seemed to have started working about 2 months or so ago.... (Using Microsoft 365 Apps for enterprise). Initially it was only Outlook that seemed to work... But tried just now with Word and OneNote, and both of those seem to be working now as well to paste images, where a couple months ago they did not.... Attempts to select more than a couple paragraphs of text/images at once is still not working, even with the same O365 tenant apps...
Attempts to paste the same items into Wordpad results in just the text being pasted with no image... However, if I copy the paste the text/images into Word first, and then CTRL+A / CTRL+C to select all to clipboard, I can then paste into Wordpad with the image.
As can screenshot images, use Teams in browser to save the images off to disk and then paste into other apps, using "compliance" as the reasoning for why general clipboard copy/paste functionality with Teams is awful does not seem to be fully accurate, especially given several issues with it across apps in the same tenant. It is refreshing to see there have been some improvements, but several years after the product was released, much of it still seems beta quality compared to several prior MS, and other vendor products it is advertised to replace.