This is a sector I have travelled on for the past 15 years. I’m also waiting to book Valencia to Cordoba for early 2025. The train you mention, the fastest departing at 9. 14 a.m. arriving Cordoba 12.42 p.m. (with no change in Madrid) is the one I have mostly travelled on.
As mentioned this option is currently only bookable up to 14 December. I’m hoping after 14 December this direct train will be introduced for early 2025, more than likely, but not 100% guaranteed.
If you decide not to wait to book for 10 January, and choose a train via Madrid with a tight connection i.e. 30 mins, you might consider booking two separate tickets to allow extra time in Madrid. 30 minutes is nowhere near enough time for me particularly at Madrid Atocha.
I book 1 ticket for Valencia to Madrid Atocha, and a 2nd ticket for Madrid Atocha to Cordoba. It doesn’t cost much more but alleviates the stress of a 30 minute connection.
The train I will be booking on the same sector as you, if the direct one doesn’t open up for 2025 is:
1st Ticket - Departing Valencia 6.57 am arriving Madrid ATOCHA at 9.08 a.m.
2nd Ticket - Departing Madrid ATOCHA at either 10.00am or 10.25 am to Cordoba.
We find January is very busy on the trains.
I hope this makes sense.