It's a calculation for the government.
If their passports lose EU visa free access, will they still make more money on the CBI than they lose out from its citizens needing to get a visa to visit EU? I would imagine the number of tourists and business travelers going from Vanuatu to EU is very, very low, so it might be worth selling these passports still.
Shutting the program down seems unlikely given how much money it generates, but if they wish to keep/regain EU visa waiver, the program might be changed to satisfy EU (improved KYC, higher requirements, revoke some passports issued to criminals).︀