It already has, because Picard remembers the bullet holes in the walls of the chateau (caused by the battle with the Spearhead soldiers) from his childhood.
And of course there's Borgati's appearance in the first episode.
That Happened to Confederate Picard in the Confederate timeline.
(Federation Picard in Confederate Picard's body time traveling from the Confederation future to the Confederation past.)
Confederate time travellers cannot travel to the federation past and Federation time travellers cannot travel to the Confederate past.
The writers made a rule, and then 9 episodes later broke it.
You saw what you saw because the writers are dumb.
They forgot about Times Arrow.
Made some bullshit up about how Federation Picard from 2368 does not exist in a Confederate future that is going to become the Confederation 2401, so Times Arrow did not happen, and 2024 Guinan had never met Picard in 1893.
For old Gunian to remember 2024, but to not have met Picard in 1893, this is a new timeline, similar to but not where we saw season one take place, even if old Guinan was claiming that she remembered 2024 before Q took Picard to the Confederation.