I don't think the plan is to train any over 63 guys. They are allowed to bid it to get the passover. Pretty sure CW is over 63, since he went to SO training 3 years ago.
From the contract
If a pilot is within 2 years of the regulated age, he may be frozen in his current crew status. A pilot so restricted shall be entitled to passover pay beginning on the date a junior pilot is activated (from the same or a subsequent posting) in a crew status the more senior pilot is restricted from holding, unless the junior pilot was activated before the senior pilot due to a base transfer or training swap. Such passover pay shall be paid on a monthly basis. Should the regulated age be altered during the term of this Agreement, the Company shall have the option of releasing the freeze for any pilot receiving passover pay under this paragraph. If the pilot is released from the freeze imposed due to the regulated age, and the pilot elects not to upgrade, there shall be no requirement to repay passover pay earned prior to the date of election. Repayment of passover pay for the pilot who elects to upgrade, but subsequently does not activate into the crew position that generated passover pay, shall be governed by Section 24.D.2.c., but only as to the passover pay received for service(s) following the date of release from the freeze.