I agree a 49 is unlikely, but it wouldn't surprise me.
The par 5s are all reachable with irons every time in low wind, without much risk. Most of the other courses have at least one par 4 that is more difficult to birdie from the tips than any of the Cabo 5s are to eagle from the shorties.
One of the par 4s is 250-something, definitely a par 3 on an Open course.
Another (I forget the number) is 280-something. This one is debatable. The only good comparison I have when trying to argue it should be a par 3 is Oakmont 8. The Cabo hole is certainly a harder shot. It's really more like Olympic 7, St Andrew's 12 (shorter tees) or Oakmont 17, a high risk eagle opportunity. The best argument that I can make for this hole as a par 3 is that none of the other holes are always reachable, including Oak 8. This one is given the low winds that have been set for the RG. On balance, it's more sensible as a risk/reward 4.
So it's a par 67, with the former 5s and the 250+ 3 among the toughest holes on the course (along with the 18th and its diabolical green). Most of the remaining 4s are driver-wedge, one is always driveable, and one or two others might be depending on wind. The remaining 3s are all mid or short irons. Taken altogether, Cabo from the babies as a 67 is probably still easier relative to par than most of the other WGT courses from the tips.