Hi Jake! The main word you missed from the article is this one:
This table is talking about files in the Drafts folder. Your file is placed in the project in a Starter team, so you won’t have unlimited pages there.
The new Starter plan teams are limited to 1 Project (folder for files) and 3 Files in it max, each with 3 pages at most. This is only applicable to Teams. If you want to store more files with more pages, you need to create them in your Drafts.
So if you want to add more pages to this file, you need to move it from the team to Drafts. You can move the file via drag and drop or by clicking the file name in the editor and selecting “Move to project”, then select Drafts: