Well technically he does not qualify yet as doesn't the B2 visa needs to be within 12 months of the expiration date? That being said, sure, I would apply as soon as the 12 month window opens according to his convenience.
As an aside, I know for USCs applying for visas for other countries, often it is good to check the validity period of the visa against the amount of time one has on their passport. I did not do that back when I last applied for a Russian visa (c. 2020). I applied for a 3yr multi-entry visa, but only had two years left on my passport, so the visa was only issued for two years even though the US will return old passports to the USCs to allow for visa usage. Anyway, I should have applied for a new passport prior to the visa application to get full return.