Hi,
Yes, that is correct. AppleCare+ does cover damages caused by liquid contact from spills (but not submerged in liquid):
"3.2 Services for Accidental Damage from Handling (“ADH Service”)
If during the Plan Term you submit a valid claim notifying Apple that the Covered Device has failed due to accidental damage from handling resulting from an unexpected and unintentional external event (e.g., drops and damages caused by liquid contact from spills) (“ADH”), Apple will, at its discretion and subject to the service fee described below, either (i) repair the defect using new or previously used Apple genuine parts that have been tested and pass Apple functional requirements, or (ii) exchange the Covered Device with a replacement product that is new or comprised of new and/or previously used Apple genuine parts and has been tested and passed Apple functional requirements."
There is an additional cost of $299.
https://www.apple.com/legal/sales-support/applecare/applecareplus/2205/220606_applecareplusmac_us.pdf