Why are keyword QS in deleted campaigns/adgroups/ads changing?

[Kobayashi]

I normally run only keywords with quality scores of at least 6 and delete the rest. Today over 30,000 dropped to 5 and they were all in campaigns/adgroups/ads that had been deleted - many years ago. Why would Google be adjusting quality scores of keywords in deleted campaigns/adgroups with no active ads? I would have thought keyword quality scores in such situations were no longer monitored? I wonder if quality scores of keywords that have been deleted themselves are still adjusted and continue to matter.

[smallcompany]

5 seems to be kind of default for non-active stuff.

[Kobayashi]

Certainly was in this case, I guess I just found it a bit odd that the quality scores of keywords in a deleted adgroup would matter to them enough for them to reevaluate them and that they would wait till many years after the adgroups had been deleted to do so.

[smallcompany]

reevaluate

Doesn't need to be that. It can be something that makes it easier for the system.
Delete action can put everything into 5 by default, that's all.

Who knows...

P.S.
I believe I noticed this with paused keywords as well (after a longer period), but cannot confirm.

[Kobayashi]

You are probably right that it was a default action for keywords in deleted adgroups rather than a reevaluation process of each keyword. Since there are just as many keywords in other adgroups deleted at the same time that still have quality scores of 8,9,10 it seems to indicate the process is done in batches and it either can take years before the batch jobs start or between batch jobs.