See paragraph 27 of Priority Pass Conditions of Use:
https://prioritypass.com/en/conditions-of-use
Chase will notify Priority Pass that the sponsor account has been closed, and Priority Pass may send you and invitation to convert to a paid account.
Ironically, I downgraded my Chase Sapphire Reserve to a no annual fee Freedom card over a month ago. Today, I received a new Priority Pass Select card in the mail?