The article says "Maximum of 200 individuals" so I think it will include the players and staff of the PBA so I don't think fans are allowed at this point in time even if you are fully vaccinated.
The PBA will try its best not to be the "super spreader" so I think they will be very strict for now and follow every protocol set by the IATF. Even if it's a fanless venue, still it is going to be exciting that even though their original plan of opening in April drew some setback but still they manage to get the nod of the IATF to finally open tomorrow. So guys ready your crypto .