A few staff as I understand it. Noone from the general public got on board until the press launch event in early April.
If that is the case that is just bonkers.
Those test trains should have went out full whether it be staff, friends of staff, regular passengers being invited for a freebie etc to completely stress test everything.
I’ve been invited to several new Hilton properties (Sister is a GM) over the last few years to do the above and I have another coming up in a few weeks time. It won’t solve all the issues but it will give the management and staff an idea of what is needed to solve known problems and identify new ones.