The reasons you provided sounds valid. But I am not sure if the math will work.
IPO of course is about getting money from the market that can be use for investment - this is ideal scenario. In this cases it is the private owner how is selling company - I am not sure how much money will be left in Sabre to use for investments after the owner will take his share.
Other think is that RIF is not precisely targeted (looks like personal skills are not key for selecting employees to be let go). That will result in limited capabilities of fighting with a competition.
Well, I guess that we will figure it out at some time.
(Me: not with Sabre for a some time already but a lot of my friends are impacted)