That sounds like rolling blackouts, and looking at it deeper looks a lot like a few minutes worth. That's not great, but it's not the same as being without power for multiple days.
Looking in my area of the SPP, they were scheduled to be one hour long, "call us if your power is out longer, especially after 90 minutes."
That's just for residential customers, commercial and industrial customers were required to shed a great deal of their load; for half a work day according to one report I read of someone who what sent home yesterday or so.
Agreed not anything like being without power for multiple days. From what I've gathered so far, the Texas grid operator had the lack of courage required to shed load early before things get catastrophic. After the northeast blackout of 1965 which resulted in a lot of reforms, a common if not nearly universal final cause of these sorts of disasters.
