You can find lot of this kind of people on the internet (look at reddit for example), they hate something and have their poor talking points to spit on something, and spread lies about it.
A new feature in Pamac sent lot of requests to the AUR server (search suggestion), when user had AUR enabled and was searching in Pamac, and because of the very high popularity of Manjaro, there is A LOT of users using Pamac, and the AUR.
The AUR server is not scaled to handle that much requests due to the new functionality in Pamac, even if the feature was implemented following the recommendation of AUR developer and using the AUR search the same way as the AUR website. The AUR server also had an issue on its side regarding internal logging, and an issue due to “poorly designed SQL queries” (word from AUR devs themselves), which was amplified by this new feature in Pamac and led to AUR outage for short amount of time (couple hours maybe).
This issue (too much request the AUR server couldn’t handle) caused Pamac requests to be blocked for a very limited time (half a day maybe) to avoid disrupting the AUR service. It also caused AUR developers to notice/aknowledge issue in their own code, and they improved on it, and worked with Manjaro devs to make it possible for Pamac to have this search suggestion feature back, which, spoiler alert, is currently worked on at Pamac side to take advantage of what the AUR devs have put in place to do that.
So you can see the situation from the classical salty kid on internet “meh Manjaro has DDOSed the AUR blablabla” (over simplification of situation as an opportunity to spit on Manjaro and spread their negativity), or you can see it from the pragmatic and reasonable point of view, issues occur because of oversight, and are fixed, and everyone improve things based on this (reality that made AUR better, and will make Pamac better too).
Look Manjaro is so banned from AUR that AUR developers come and help Pamac to be better AUR Metadata Archive (live) (#1161) · Issues · Applications / pamac · GitLab