Unfortunately we have the execute bit set on tl-run-xstartup.d and tl-run-xlogout.d, but these scripts must be sourced as they modify the environment.
Fixed in r31561.
Hopefully few customers have been trying to execute this. And if they have, then it might be a good thing that it stops working for them as they've been running with a broken environment.
Is now installed with 644 but source was still executable. Fixed in r31668.