In T301825, we added the "AND" filter to topic selection to allow users to make their filters much more specific. It is currently available only for campaign participants on Spanish Wikipedia. We are going to deploy to all Wikipedias in two stages:
# First to all accounts on an expanded set of pilot Wikipedias for two weeks: Czech, Bengali, Arabic, Spanish, Turkish, Persian, Portuguese. This means more wikis, and also relaxes the campaign restriction.
# After two weeks, we will assess any community feedback. We will also take a quick look at usage of this new feature via EventLogging (see TASK TO BE CREATED). Unless any issues have been discovered, we will deploy to all accounts on all wikis so that it is on by default for everyone.
But before we expand, we want to complete this blocking parent task, so that we are going to more users with improvements included: {T305097}