How to get rid of develop branch for simplified Git flow
Let's say you take out the master branch  (you can rename develop to master to confuse your team if you like later) and simply use tags for releases either on develop or hotfix branches. You took out a branch, but the difference is just a change in syntax. Change for change sake.

Now let's say you actually take out develop with keeping the locked master branch. What will happen is that integration of code will slow, it will live longer separated in feature branches, especially close to release dates. This will Increase the difficulty of merging each time and slow the process down.

Within the constraints you have laid down I don't see any positive effects of making such change. It would require relaxing the constraints, especially the first one.