Um, yes they can shop for a hit. You simply add a track or two and throw more money on fresh promotion. Many songs chart with the album release so they can recover but they said, plane as day, that they are adding new inspiration to the album, that means new tracks. Hence the month delay.
You can shop for hits. Loads of hit songs we know bounced around from artist to artists till it was purchased for an album. Writers can have songs out there for days to years. Other times you can hire an artists to come make you a hit as Morgan Wallen and Beyonce have done repeatedly. Chappell Roan used the same producer/writer (Dan Nigro) as Olivia Rodrigo for her two big hits "Good Luck, Babe" and "Hot To Go". Jive Records flew 16 year old Britney out to Europe to work with Max Martin on "Baby One More Time". Yes, you can shop and buy a hit.
Shawn may have songs ready or is looking for fresh songs but I expect we will see some big named producer on the lead single for the album release.