I presume by submission layer you mean remote control? The original noirlab press release noted that the "Mid-Scale Observatories (MSO) network" was disconnecte

I presume by submission layer you mean remote control? The original noirlab press release noted that the "Mid-Scale Observatories (MSO) network" was disconnected as a precaution (which is likely some kind of site-to-site VPN), which is likely the only way to connect to the telescopes remotely (the mention of "service mode" means that people can still request observations, but they can't do them themselves without flying out to site). Service mode is becoming quite common on larger telescopes, with smaller ones heading towards automation (and being single purpose).