What is the travel risk for an EB-5 investor with approved combo card: I-131 and I-765?

That concern is valid. Currently, USCIS is holding I-485, and their I-131 and I-765 forms as well. But they may reevaluate that in 2022. Any travel with the AP alone comes with a risk of CBP denying entry, so I typically recommend that travel with AP be done only if really necessary.

It should be fine.

Since you have a pending adjustment of status and a valid combo EAD/Advance Parole card, it appears that travel would be acceptable. It is best to consult with counsel with more details prior to any departure.

First, we can expect Congress to reauthorize, but this will take a few months. Second, if you have no underlying status such as an H-1B visa, you will almost certainly be able to reenter regardless of your advance parole. USCIS has indicated it will review its policy on issuing derivative benefits to pending RC-based adjustments at the end of this year, so if you want to be conservative, wait until that announcement and if you have an H-1B, there is zero risk. There is only a very small chance USCIS would automatically revoke lawfully issued advance parole that allow you to return prior to the authorized re-admission date.