So, I did a little digging, and apparently Prop 54 amended the state constitution in pertinent part as follows:

No bill may be passed or ultimately become a statute unless until the bill with any amendments has been printed, and distributed to the members, and published on the Internet, in its final form, for at least 72 hours before the vote, except that this notice period may be waived if the Governor has submitted to the Legislature a written statement that dispensing with this notice period for that bill is necessary to address a state of emergency, as defined in paragraph (2) of subdivision © of Section 3 of Article XIII B, that has been declared by the Governor, and the house considering the bill thereafter dispenses with the notice period for that bill by a separate roll call vote entered in the journal, two thirds of the membership concurring, prior to the vote on the bill.

Given that the legislature hasn’t been voted on yet, the publishing on the internet could be done immediately and satisfy the constitution. Alternatively, if the Democrats want to keep the plan secret until the last minute, Newsom could provide a written declaration of emergency, and since Democrats have a supermajority, they could easily provide the concurrence without a single Republican vote. Accordingly, I don’t see the Republicans winning on this issue.