There's no way to know, but you need to bear three things in mind - two in favour of "not random" and one complication:
It absolutely was not random in GT Sport. You could actually test it and, yes, it always delivered the same cars from Daily Workout tickets in the same order no matter what you did, and it seemed that it was simply repurposed GT5 UCD code. Reusing code is not exactly an unusual practice.
The order changed after content updates too, when new cars got put into the list. So do GT7's ticket rewards...
But of course GTS's tickets were just cars every day. GT7's are complicated by the fact that there's eight different types of them, at six different levels, and the rewards that each can possibly deliver vary too.
We can't check how GT7 works as we did with previous games, but it's not much of a stretch to assume that there's a predetermined list you rattle down each time you meet the requirements (like GT5 and GTS), with Collector Level modifiers for the ticket stars.
Which is what GT7's online saves are set up to prevent, and why we can't check how it works.