Hello!
I'm the Product Manager on our LTI team, and I'd like to help clarify this change. This will only affect instances set up as consortia (where the root account has "Consortium parent account" selected under Settings in the "Canvas Cloud Information." section.) Additionally, this will only affect child accounts which are set as "not a primary settings root account." So far we are only aware of one institution which has this configuration, so I don't believe anyone in this thread will see a difference. The change for those accounts is that the developer keys will not only work for the subaccounts, but will be available without user intervention. We are working toward providing more features for centrally managed consortia which require identical setups in multiple root accounts, and this is the first step toward that goal. My apologies for the lack of clarity, I will work to improve these notes in the future.
Please let me know if you have any further questions!
Alexis