If you do proceed I would say use an open-ended fund that you can exit anytime, preferably one traded on the open market: Comparison of three open-ended funds from GV Portugal
That way you are at most out some lawyer fees for uploading the initial application (a couple thousand? Maybe can negotiate it lower?) if the rug is definitively pulled. You can just liquidate your investment.
But if they add in 5-year path grandfathering for people who already applied, you might benefit from that.