I wonder if NDOT and the city of Henderson will do with the future Via Nobila interchange on I-15 what the city of Lone Tree and CDOT did with the Ridgegate Pkwy interchange on I-25. When the Ridgegate Pkwy interchange was constructed, CDOT got rid of the very substandard Exit 191 and built a frontage road (Havana St) on the east side of I-25 to connect Ridgegate Pkwy with Castle Pines Pkwy (Exit 188).
In the case of this future Via Nobila interchange, NDOT could easily get rid of the Sloan exit and have everyone use Las Vegas Blvd to reach those businesses at that exit while building the new Via Nobila interchange to the correct standards.
A future Via Nobila interchange bridge would be about a mile south of the St Rose Parkway bridge over I-15. The Sloan exit is another mile further south from the future Via Nobila. The I-15 ramps for St Rose Parkway are quite long, extending almost a half mile south of the Parkway itself. A new interchange should include C/D lanes even if they remove the Sloan exit, though NDOT has plenty of experience building C/D lanes in Clark County.
There are long-term plans to rebuild the Sloan interchange. This has actually been in long-term plans since the I-15 south EIS was completed circa 2008—that study led to several projects that have since been constructed, including the major I-15 widening and C/D road project that included reconstruction of the Blue Diamond interchange, the added Silverado Ranch interchange, and the recent added Cactus Ave interchange.
However, it now looks like the Sloan interchange project is renamed Via Inspirada in NDOT's latest major project quarterly update report. So I assume that the Sloan interchange is now not going to be rebuilt in its current location, but rather a bit to the north. If a Via Nobila interchange (formerly Bermuda Rd in earlier project updates) is also being built in between Via Inspirada and St Rose Pkwy, there's no way these three don't at least have braided ramps (I think C/D roads are unlikely).