For the launching of the service, sure, but for simulated testing? They've already been running test trains, it's just more now (or will be). Can't think what they'd need senior management on hand for.
And even for the launching of the service, I'm not convinced it's a problem. As indicated previously, all the suits made it out for the opening of the Spadina subway extension in December 2017 despite it being on a Sunday. And June 18, 2016 (Saturday), they had a ceremony for the opening of the streetcar line on Cherry Street.
Yes, those are opening dates. I haven't been able to find any information on when trial operations started on either, but there were various non revenue rides for VIPs, employees, and then the public, on the SRT from July 5 - 8, 1984, and then again on a handful of other days leading into mid August 1984, so they must have been at it for a while.