We have updated all our custom apex to be in the newer api versions (31 and above) to be ready for the end of life of the older api versions https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/api_rest_eol.htm
We have a few managed packages that still contain apex with older api versions but is says here that these are not affected by the retirement https://help.salesforce.com/s/articleView?id=000389618&type=1
Still, we keep receiving emails from Salesforce that we need to do something with regards to this api retirement, we are unsure what.
Did we miss any apex or other things affected by this api retirement?
Thank you in advance for sharing your thoughts on this.
Manoj Nambirajan (Dell Technologies) 
Forum Ambassador
check if any apex classes has a web service linked with it? if so you have to focus on that for upgrade.
as well as any external integrations thats consumes a lower version api
