Weibo link not shown in Help tab
According to the spec, Chinese users should see a link to Weibo instead of the other social networks. However, we removed the PNG for that link together with the ones for all the other social networks as part of trac#6749. Therefore no image is currently being shown. This regression was introduced in release-2018-4.
Furthermore, the link is only shown for the locale "zh" but not for "zh_CN" as well as "zh_TW" so, presumably, it's not actually shown for Chinese users. This doesn't appear to be a regression.
Finally, the link is not being assigned a URL due to this open change. This regression was introduced in release-2018-5.