Hello,
Valgaaf here (an editor of this wiki and a mod from our Discord Server). The reason why most of the Alicization arc episode pages do have have plot summaries is that currently there are very few people working on that - to be honest only me and Gsimenas add something to anime episode pages from time to time.
While I don't see anything against your help in that area, please be aware that we expect an appropriate formatting, style and tense when writing an episode summary. Also, Gsimenas is currently the only who has enough skill (and determination/strong will?) to review and edit those summaries so that they are written in the top quality - though I plan to start reviewing in near future as well.
Of course, there are other articles that need to be worked on, but since you are Anime Team, I understand you might be not interested in them.
Cheers!
Valgaaf