It's very much not odd.
You can't, and never have been able to, take a mandatory pit stop before you cross the start line on-track for the first time or before you cross the finish line on-track for the last time - and I write this almost every week in the article when there's pit strategy. Of course I didn't this week...
It's the same deal in real world motorsport too, except that one time when F1 forgot to include it in their rules and Michael Schumacher won a race (British Grand Prix, 1998) by taking his ten-second stop-go penalty in the pits at the end of the final lap - with his pit box after the pit lane timing line (there isn't a start/finish line in the pits; it's a timing line) so that he didn't actually serve it...