While I very much support the idea of closing old tickets (as well as Gerrit patches) that don't look like they will ever be tackled – this tends to be a delicate decision that benefits a lot from being as open as possible. There is not much to add to what AntiCompositeNumber already wrote.
1. While 61 tickets is not a small number, it's not a large number either. People are typically not subscribed to all tickets the same time. I, for example, would have received a single notification email.
2. I, personally, disabled almost all Phabricator emails. For example, removing a tag it rarely something I care about. Feel free to suppress such notifications, esp. if you own the tag. But having a ticket declined is a relevant information for me, if not the most relevant.
Overall I think it would have created less irritation and stress to just let Phabricator do what people expect it to do.
Here is another look at these 61 tasks, in case people are interested: https://phabricator.wikimedia.org/maniphest/query/qJdT7nxCgmK3/#R
Kind regards Thiemo