Yes, character specific missions for T and M like Strangers and Freaks are not required for the 100%.
First, I went to look for the 100% world record of GTA V. The reason is that the ending C is the one that takes the most out of the 3 so I didn't think that it was the ideal time-wise for a speedrun.
At the time of writing, the record is held by burhac with 09:32:12. I started scrolling the VOD until he went for the last mission of the game.
When Franklin has to pick an ending, he chooses B:
I continued watching the speedrun until he had to play the selected ending, and I confirmed again that it was the ending B:
After completing that final mission, he finishes the run and opens the 100% completion tab on the stats section of the pause menu:
Behold a 100% savegame with an the endings where one of the protagonists die.
At the end, a 100% in Grand Theft Auto V with the endings A or B require the following:
- Story missions from Prologue to Something Sensible/The Time's Come
- Lester's Assassinations (unlocked after Fame or Shame)
- 14 Random Events
- Strangers and Freaks for Franklin
- 42 Pastimes
- 16 Miscellaneous Tasks