I stopped by Rinconcito Yucateco today and it is open!
I asked if it had changed owners and/or closed a couple months ago. The lady said that there was a problem in the kitchen that required them to closer briefly for some repairs. There nothing in the restaurant inspection record from that period so perhaps not health department related.
El Rinconcito Yucateco
3935 Sebastopol Rd
Santa Rosa, CA 95407