I think the best that anyone could expect from an IPO is an ESPP (employee stock purchase plan).
This is industry stand for publicly listed tech companies and it typically allows you to buy stock at a 15% discount capped at typically around 15% of salary to a maximum of around $30k/year. So about a $4,500/year benefit is typical. On top of that, new hires often receive RSU's (restricted stock units) and top performers and very senior execs will get stock grants as part of their bonus package.
The reason there are so many multi-millionare individual contributor software devs, is not because of their salaries, it's because they went all in on ESPP and accumulated their wealth through big increases in stock prices.
That won't happen at SAS as it's hard to see SAS's stock price growing significantly given the major internal and external challenges it faces.
So really, I don't think there is much upside for SAS employees. As for the downside, well that's pretty obvious...large scale redundancies demanded by Wall Street analysts and activist investors.
A better option for employees would likely be a buyout from the likes of Broadcom. It's a shame that deal fell through as it could have benefited the surviving employees by several hundred thousands dollars each, as has happened for VMWare employees who were retained and awarded RSUs. But, of course it comes with the same downside as IPO - large scale redundancies.
Either way, large scale redundancies are coming, so it would be wise to prepare.