GM should make it clear up front how they're ruling per game. If not, you'll be in awkward place of misaligned expectations and probably players looking for another game/table.
Well, I usually play with the same group of players, so we all know the deal.
For those times I am with a new group of people, I like to spend the first session building the characters all together, while we discuss both the general plot of the campaign (so they know what to expect), go over any "Rules of Issue" such as house rules, or how I determine certain things that are ambiguous. I Also listen to the players, and get a feel for what they are expecting from me as the GM as well, and consider any house rules they may be used to. This also allows me to customize the campaign around the party, and to cover for any group weaknesses. After all, there is no point in me wasting my time with loads of Matrix events if not a single player is playing a matrix based character. Nor do i want to be throwing lots of awakened talent at a largely mundane party.
The idea is for everyone to enjoy themselves for the night. I'm there to tell a Story. The players are the protagonists, from there, I have no idea where it ends; That's up to the players.
BUT, This is a bunch of blokes sitting around a bar table or on basement couches! This is not organized Missions Play. For that there has to be a solid grounding of rules and resolutions, as the expectation is I can take my character and play in Vancouver one week, and then in New York the next with an entirely new group of players while still advancing an plot.