Today we had some load issues re people running winxp on try. We only run winxp on beta etc and thus have limited capacity in this pool. We think that this may be due to people running them via trychooser https://mozilla-releng.net/trychooser/ We should indicate in the trychooser page that this platform is not supported. It might be good to split out all the platforms that are in the process of being deprecated explicitly on this page so people know not to run them on try due to limited number of machines being available.
I was mocking something up to show what I want, but it turns out that pretty much fixes this bug. Taking.
Rok merged this. It should go live on Thursday.