Yes it is feasible. Using the Topics Only Visible to OP mod, you even have a fairly close approximation of what you need to happen functionality wise.
From this mod, a few things would need to change
- The
viewtopic.php
instructions would need to account for post creation date and user creation date instead of being for the original poster - The
viewforum.php
instructions would need to account for first post creation and user creation date instead of being for the original poster
After look through the installation instructions and changes you'd need to make, it seems those are the two biggest changes required. The ACP changes appear to be more wording, and the variable names could probably be slightly more appropriate since your mod won't be about only the OP seeing the post.