Santander Direct Debit cashback review

My latest statement says:
Changes to cashback for Direct Debits
Following a review, we've identified some direct debits that aren't eligible. We'll stop paying cashback on them from 1 December 2018 in line with the account terms & conditions. No other changes to the features or benefits of the accounts are being made at this time."

There is no other information about which direct debits are no longer eligible, although the website sets out which are eligible and contains a tool to use to determine if your organisation is included.

I suppose this is standard practice, reviews of this nature?