6-206 has been interpreted to mean in the suite. Especially if the main is in a room not readily accessible to the Tennant's. IE 24/7/365 without having to awaken or call in a caretaker first.
Having said that Who ordered an upgrade? In what province and under what regulation?
Generically if the installation is well maintained and still adequately serves the purpose under which it was approved then there are no requirements to upgrade. see 2-300 to 2-322. Obviously a service upgrade could trigger the Main breaker thing in the suites.
It can be pretty hard to force upgrades without some other legislation besides the current CEC.
In BC for example most Knob and Tube replacements are forced by the Insurance industry who may also require a minimum 100 amp service. These upgrades are not mandated by the CEC at least not if the K&T is in good condition and meets the needs of the residents.
Same with a service size. A modern home must have at least a 100 amp service but in 1963 the 60 was code compliant and if the loads did not change what could justify the upgrade? Only poor maintenance, failure of the service, or a load increase or a law being passed.
