Even more so when that person later loudly proclaims that they never made such a request, even when provided with written proof.
I can of course not say whether the people currently working at Twitter did warn that the recent measures could have such major side effects, but I would not be surprised in the slightest, considering their leadership's mode of operation.
Even as someone who very much detests what Twitter has become over the last few months and in fact did not like Twitter before the acquisition, partly due to short format making nuance impossible, but mostly for the effect Tweets easy embeddability had on reporting (3 Tweets from random people should not serve as the main basis for an article in my opinion), I must say, I feel very sorry for the people forced to work at that company under that management.
Though it’s hard to know for sure what really went down. Could be a number of things. Including a lack of subject matter experts (Elon recently admitted to laying off some people they shouldn’t have).
On that note, the 10 requests/second in the post is also negligible for the same reason. Only requests that hit backend servers matter
Personally I'd just cache HTTP 429 responses for 1 minute, but you could also implement rate-limiting inside the load balancer with an in-memory KV store or bloom filter if you wanted to.
Perhaps the context you're missing is that all large sites use ECMP routing and consistent hashing to ensure that requests from the same IP hit the same load balancer. Twitter only has ~238 million daily active users. 10 requests/second on keepalive TCP+TLS connections can be handled by a couple of nginx servers. The linked "Full-stack Drupal developer" has no idea how any of this works and it's kinda sad how most people in this thread took his post at face value