I think that on balance I also agree with the decision.
As things stand Brand has not even been arrested, let alone charged or found guilty. The allegations are very serious. I imagine that his lawyers will also be on the look out for potential defamatory comments online.
Whilst in theory you could have a thread for the Dispatches episode to cover the surrounding presentation related elements it could easier veer into posts that could cause problems for users, mods/admin and the site. Allowing a thread where posts are pre-approved might have been an option, but that creates extra work for mods & admin.
The wider subject of sexism in comedy and behaviour or some male comedians in general is probably a topic better suited here rather than pres.cafe.