Answering to my own question:

What is the change?
The legacy single response report is a URL that displays a report for a single survey response. It is formatted like below:
https://qualtrics.com/CP/Report.php?SID={surveyId}&R={responseId}&ResponseSummary=True
These URLs are no longer generated by any workflows in the Qualtrics platform. However, there might be users in your brand who manually created these URLs in email triggers or email tasks, by using piped text to add the responseId into the URL. After February 18, 2023, these URLs will no longer work, and will instead return an error.

What action do I need to take?
Forward this email to users in your brand who might be manually constructing these URLs. 
Any email task or email trigger where the user has manually created the legacy response report URL needs to be migrated to use the new single response report solution. There are 2 ways to switch to this new solution:

1. Create an email task via Workflows and enable the “Include Response Report” option. This will automatically include a response report link in your email.


2. Use an embedded data field in your email task to pipe in the new single response report URL. The format of the piped text is

Does this affect surveys that are being distributed to a second respondent? For instance, person 1 completes part of the survey, and then it's sent to person 2 to review their response and then sign off.

https://community.qualtrics.com/XMcommunity/discussion/comment/53208#Comment_53208I think it depends on what sort of link you are using. The above one is a static report on responses. If you are using some sort of dynamic link in "editing" mode", I would double-check with Support.

Is there any way for me as an admin to search for surveys using this format? I've received the email warning me that people in my org are using it, but I don't know who. (If Qualtrics can tell that we're using it, I wish they'd give me a little more guidance on who is using it.)

https://community.qualtrics.com/XMcommunity/discussion/comment/53225#Comment_53225At least you have received one. I am a brand admin and this email was forwarded to me by others
I guess if Qualtrics knows that certain links have been used in a brand, they should also know what IDs are used there. So one can track the surveys.

Good morning from a snowy Sweden!
https://community.qualtrics.com/XMcommunity/discussion/comment/53225#Comment_53225If you have the survey ID you can perhaps check who logged in and applied changes to that survey the last time?
Or check who logged in latest and start from there?
Detective work is fun :)

Mattias, I WISH that I knew the survey ID. All I know is that "someone in my org has used a link with that format in the past 30 days." I don't even know if it's a new survey or an old survey!
Detective work IS fun. But the scope of this, with the available data, is huge.

https://community.qualtrics.com/XMcommunity/discussion/comment/53278#Comment_53278GAH! Frustrating! And Qualtrics Support is not able to backtrack this somehow? I just feel if it's triggered from them, the data should be in their systems somewhere...
Good luck! :)

https://community.qualtrics.com/XMcommunity/discussion/comment/53282#Comment_53282Thanks for the confirmation that I'm not being unreasonable!

I received the same email and am very confused. I currently use the "Include Response Report" on all post survey email triggers that I have created. So, what changes do I need to make?

Back to the topic...
as we have started to use new format of the links, they now return an error that request expired. Is there an expiration period for those?

I am not a fan of this change of removing the viewable response as I do not use email triggers anymore and there is no API to retrieve a viewable response (if there is an API call I would like to know about it).

I am confused by what's happening. The old links still seem to be working today? Is that the case for anyone else?

@MsIreen , how are we using it in embedded field now?