[Scott Maier]

This doesn't sound any different from the behavior in 5.1.3 and earlier releases.

You need to have the focus on the tab drawer before you can paste in to it. Clicking empty space in the drawer gives it focus, or you can click a tab, wait a moment (to avoid a double-click, which opens the tab in a new window) and then click again to bring focus to the drawer.

Certainly if you can outline a scenario where the behavior is different than it was in older releases we'd like to know about it so we can fix it.