They could just put electrical tape over the tigerair logo, that’s usually the case like after me bank dropped Storm they just put a patch over itThey probably went into production after RedZed and Grill'd were added but before Tigerair left.
I don't know if you've noticed but a new batch of player issue away jerseys are being worn by some players but not across the board. The RedZed logo has a white backing and the new ISC lined gel grips. Still with Tigerair logos so they probably want to keep things consistent I guess. They probably don't want to deal with patching things up unless they have something to cover it with.