I never tried this configuration work. however, worked many time and did configuration on the context ASA.
if you do remove the command. for example,
Context Alpha
allocate-interface gig0/0
allocate-interface gig0/1
no allocate-interface gig0/0
config-url disk0:/Alpha.cfg
so lets walk though on the above config. The cfg configuration is kept in asa flash. in case if you give command no allocate-interface gig0/0 in that case your nat/interface configuration in the context will be gone. (I assume so, I never tested this). for the allocate-interface gig0/1 you have to do the nat/interface configuration in the context.
also make sure you do issue the command config-url disk0:/Alpha.cfg.
Also take away is make sure you have a configuration of the firewall of the each context in case if you have to revert back. get the change window in place. than do it.
please do not forget to rate.