This is just flat out WRONG.
Statistically speaking, the TX grid is just as reliable as any other grid in the USA:
https://www.nerc.com/pa/RAPA/PA/Performance Analysis DL/NERC_SOR_2020.pdf
I lived in TX for more than a decade, the fact is that this place is NOT prepared for temperatures below 20F, period. They just don't see them often, and if they do they are NOT sustained like they have been during this cold period, so the power generation facilities (FF, nuclear, and renewables) are not weatherized like they are further north.
I talked with a friend that lived in Dallas for 50 years, and he says he has only once seen it this cold for this long, and that was ~25 years ago. Grids are simply not built for these edge cases, period.
All grids have edge cases where they have problems: i.e. the Western grid was woefully unprepared this past summer for the drop in solar production due to skies filled with smoke for weeks on end.
EDIT - I do agree that TX will continue to lead the nation in the transition to renewables, but it won't have much to do with this cold snap. It will continue to be the pricing of renewable power, nothing more, nothing less.