It really is an obvious hint. Anyone can check that since the blackout there is never less than 4000 or 5000 MW of nuclear at all times (compared to 3000 MW of nuclear in the days before the blackout).
Also combined cycle. On the day of the blackout there was very little, about 1600 MW. Now there is usually never less than 3000 MW of combined cycle even at peak hours of solar generation.
Even in the report they released they talk about how just 10 minutes before the blackout they were scrambling to put online more conventional generators to stabilize the grid (they never had the change to go online before the blackout happened). [1]
"At 12:22 h when the system recovers from EVENT 2, it is observed how the system voltage starts to rise, but within the operating margins. In view of this situation, the REE Control Center begins to couple reactors in several substations to counteract this rise. [Likewise, [...] the decision is taken to couple more conventional generation that complies with P.O. 7.4 mainly in the south, asking for coupling times. A CCC group is chosen in Andalusia, which gives 1 h and 30 minutes of coupling time to the grid, technical minimum at 14:00h. This measure was never implemented due to the zero voltage. Coinciding with this decision, a control center reported that a nuclear group was oscillating a lot with the oscillations and that it could trip. As a precautionary measure, advance notice was requested to couple to another CCC group in the North zone. Then, another control center indicated that a CCC group in Andalusia needed between 2 and 2.5 hours to couple and asked to modify the offer to make it cheaper. After this, the first control center confirms that the northern CCC group would couple at 15:00 h. [...] As a result of all the above events, the system was at a very different operating point from the initial one, with low damping and less flexibility in voltage control. [...] The corrective measures taken could not be fully implemented, e.g. synchronization of the two groups."
