Priest talent · row 1 of Holy, from level 10 (5 with Talented 5/5) · Physical

Twilight Focus

Gives you a 23/47/70% chance to avoid interruption caused by damage while casting any spell.

Game files · build 1.60.1.70245Read from the WoW Forever beta client, build 1.60.1.70245.

Compared with Classic

Classic tooltip

Gives you a 35% chance to avoid interruption caused by damage while casting any healing spell.

Data	Classic	Forever
effect 1 value	35	70

What Blizzard said about Twilight Focus, each line checked against the files.

Matches the files
Starshards now correctly gains resistance to spell pushback from the Twilight Focus talent.
The files In build 70009 Twilight Focus (14913) added Starshards to the spells it affects: its spell mask gained bit 0x200000, the class flag all 7 Starshards ranks carry.
Twilight Focus Starshards Development Notes, September 24
Matches the files
Twilight Focus: Formerly Healing Focus. Now grants pushback protection on all spellcasts, but costs 3 talent points instead of 2.
The files Classic's Healing Focus had 2 ranks at 35/70%, healing spells only. 70245's Twilight Focus has 3 ranks at 23/47/70%, any spell (spell 14913).
Twilight Focus Class deep dives: Priest and Warrior