Are rules and exclusions often removed as part of rules and exclusions updates?

[tacotuesday 0]

I went to modify one of my exclusions today and can no longer find it.  I couldn't find the corresponding rule either [Y0064].  Are rules and custom exclusions often deleted as part of a rules and exclusions update?  I'm guessing this occurred today for the 1049 update.  I actually can't find any of the rules that started with Y.  I believe they were titled "Enrichment".

Is there a change log for rule and exclusions updates? 

If Y0064 ever comes back will my custom exclusions be restored?  I had quite a bit of time into writing those exclusions.

[Marcos 5,739]

We haven't been reported such issue so further investigation will be needed. Please raise a support ticket.

[tacotuesday 0]

I'll open a ticket.

Just to keep anyone updated who is curious.  I found a past detection of Y0064 and selected edit rule.  When looking at the details, it appears the rule has been deleted.