This doesn't appear to work currently after validating this in a development environment.
Note that when you do utilize the 'Remove Flow as Admin' activity for Cloud Flows, the Environment Name and Flow Name have to be very specific, and the Flow Name is not the name of your Flow - it's actually the Flow's ID, which is a Guid.
The easiest way to find both values is to navigate to the details of a specific Flow and note the 2 values from the url based on the format below:
https://make.powerautomate.com/environments/{Environment Name}/uiflows/{Flow Name}/details
While a Cloud Flow can be removed using the 'Remove Flow as Admin' activity, following the same process for a Desktop Flow does not delete the Desktop Flow.
Successful deletions result in a 200 status whereas unsuccessful ones seem to yield a 204.
Find this post helpful? Please mark it as the solution and/or provide kudos so that it will help others in the future.
Cheers,
Matt