I think the timing is interesting.
I think the timing isn't interesting at all. I think it is/was about as predictable as it could be.
That said, I'm surprised she made the announcement as quickly as she did. I kinda expected something like this maybe a week or two from now. IMHO, she jumped too quickly, which gave away her backroom game. If she'd opted for a longer timeline before announcing, it would have looked more sober, considered. It would have been slicker, more polished. Instead, she's given us optics of the breathless excitement she's feeling for the execution of her next planned phase.
This Senator had already planned to employ an 'if this/then that' stratagem going forward.
And either choice/outcome would serve to burnish her brand, going forward:
1. If Herschel Walker wins the run-off, Sen. Sinema will hold pat- do absolutely nothing. Continue working her brand as the
sometimes (strategically) independent 'X-Factor Democrat.'
2. If Raphael Warnock wins, Sen. Sinema will symbolically bolt, continue to caucus/vote Team Blue 90% of the time (like she always has), and maintain her 'Arizona Maverick Lite' brand.
3.
*bonus* It also insulates her from primary challenge from the Dem party, in which she'd be very vulnerable for re-election.
This is being blasted on the news cycle as a bombshell, but it's really just a blatant and predictable example of cynical political calculus.
They get on our screens every day, then play chess like chimps... on a national scale.
Transparent as Saran Wrap.