I agree that the CBA and potential work stoppage are factors that are influencing this process.
If you are Boras, you are advising your client to test the market before a salary cap is possibly introduced.
If you are Ilitch, you are not going to bid against yourself in a situation where mega contracts may become obsolete.
Finally, I don’t believe for a second that Boras is in charge of Skubal’s decision. One does not become the best in a highly competitive field by being stupid, lazy, or passive. Skubal will make his own decision.