The addition of archived webcast videos to TBA is a crowdsourced thing - if somebody doesn't do it, nobody will. So if you want to see videos organized there, help us out by adding them and keeping the site up to date.
TBA has a
Google Docs spreadsheet where you can link YouTube videos to specific matches. From there, the links are imported periodically into the TBA database. If you find matches on YouTube that aren't there yet, do the community a favor and add them.
For harder to work with formats, such as YouTube playlists or big chunks of raw webcast video, I wrote some
python scripts to help take some of the menial labor out of the process and automate some of the parts. If you know of any webcasts that have been archived, you can download the video and split it up using one of the scripts and then automatically upload it to YouTube.