Tickets are not for assigned seats, they are for a certain fare and class of service, a certain flight (date, origination and destination).
Seats are assigned on boarding passes.
I don't know if the vernacular makes any difference in this case.
When I've booked flights, on every single booking I've done, with Southwest being the exception, I've bought and paid for particular seats with my ticket purchase. Sometimes there's a need for a change when boarding, and the boarding pass will be changed to reflect that, but most times when I did fly, the ticket and boarding pass both reflected my seat assignment.
I say this noting that the last time I flew was in March, 2014, and prior to that would have been July 2010. I'm not keen on dealing with the bullsquat of flying commercial these days.