ERCOT didn't declare any capacity emergencies on that day, or any recent day. Is it possible you just suffered from a stochastic outage, and not a capacity-related intentional disconnection?
Pretty unlikely. Outages are common, especially in this above average summer, due to higher transformer load and temps.
Ever since the freeze, people who have even planned outages, refer to them as “rolling blackouts”. ERCOT is a pretty open data organization aside from QSE and generator data, and it’s unlikely that this data would have been fudged. We would have seen EEA3 in addition to $5k settlement prices if there was enough of a shortage to invoke rolling blackouts. These prices directly affect end users, e.g. businesses, datacenters, end users still on RTM rates, and solar buyback users. Generators definitely have offers open up to the $5k price point, and there is no way they’d be able to lock the settlement price without it being obvious to businesses/end users, or to generators/REPs/TDUs that there is market manipulation.
As far as sagging frequency, this is also wrong, because frequency sag calls up additional reserves, and we haven’t run below 1 gigawatt of reserves since the winter freeze. The number to watch for is 59.5 hertz, which is automatic EEA3 (we haven’t hit this since the winter storm, where we reached a whopping 59.3 hertz) This is also directly measurable by TDUs and (maybe) end users.
The hypothesis that there was a rolling outage invisible to everyone except one guy on a forum doesn't strike me as being very likely. Just an ordinary power outage seems a lot more likely.
https://www.ercot.com/services/comm/mkt_notices/opsmessages