As quoted from the linked post.
It looks like you’re part of one of our experiments. The logged-in mobile web experience is currently unavailable for a portion of users. To access the site you can log on via desktop, the mobile apps, or wait for the experiment to conclude.
This is separate from the API issue. The are actually going to BLOCK you from even viewing reddit on your phone without using the official app.
Archive.org link in case the post is removed.
Make sure it actually overwrote all your comments. PowerDeleteSuite doesn’t respect the edit rate limit. I used a fork which runs much slower but respects the limit.
Also, it’s a good idea to wait several days between the editing and deleting your account. Many users on reddit were suggesting that reddit holds on to pre-edit text for a while. Obviously archives hold onto it forever, but if your goal is to deny your content to reddit, that’s orthogonal.