While not in the actual archive, Ubuntu users do have several options. It's in my PPA, they can download the proper .deb files from Debian, or they can use the superior Remmina. I'll admit I was reluctant to move to Remmina, but since having packaged the corrected tsclient version for my PPA, I have done so. I do wish that Remmina had an import/migration option for tsclient files though.
While not in the actual archive, Ubuntu users do have several options. It's in my PPA, they can download the proper .deb files from Debian, or they can use the superior Remmina. I'll admit I was reluctant to move to Remmina, but since having packaged the corrected tsclient version for my PPA, I have done so. I do wish that Remmina had an import/migration option for tsclient files though.