weekend availability?

hi everyone! i am a long term partner and earlier this year everyone at my store was told by both my CHL and DM that open availability is required to keep our jobs and if that doesn’t work for us then it’s time to start looking for employment elsewhere. when i questioned both of them about it they said that this is a policy being implemented across every store in the US. i call bs but maybe this is true? is anyone else’s store suddenly requiring partners to work fri-sun regardless of their availability?

i am worried because i have very important obligations on sundays and ever since they’ve started scheduling me sundays i have to beg every partner i know to cover my shift for me. me not being available sundays has never been a problem up until earlier this year.