They need to have certain capacity in the stock structure BY LAW in order to maintain their lease agreements and other financial terms.
The current A/s minus O/S is getting low and you only have the annual meeting (or a special meeting) to ask for more in the A/S so it is prudent to do it now.
Market value is unchanged afterwards.
Also if you look how the recent cash raises using treasury stock has gone it will not be viewed as dilution. May be they need it to build a factory (as part of a JV) in china? May be to build a new factory for Amazon deliverable so they have dedicated production line?
Currently they have no plans but it is their FUDICIARY duty to maintain a capacity to raise cash without calling special meetings to meet their commitments