California has to adopt a new license plate plan soon - see https://manifold.markets/StrayClimb/after-california-runs-out-of-plates
When this plan is announced market is YES if it will allow for nonalphanumeric characters, from other languages, such as chinese characters, hindi letters, native alphabets, etc. Note that english punctuation doesn't count, but non-English language punctuation would.
Spanish Ñ or ñ would count as YES, as would foreign accented letters for example umlauts, or accented spanish or french vowels.
This can resolve as soon as the new plan is finalized +3 weeks.
Kids Specialty License Plates already allow "a hand, heart, star, or plus sign" in the license plate, though I guess it isn't considered part of the value
https://www.dmv.ca.gov/portal/vehicle-registration/license-plates-decals-and-placards/california-license-plates/special-interest-license-plates/