Adding a loft bathroom

[pkirk28]

I would like some advice please. We are in a condo with a loft. Our unit is on the top floor of a 3 story building. We would like to add a small new bathroom in the loft directly above an existing bathroom on our main floor. The 3 fixtures in the existing bathroom are individually vented but all drain into the 3” vent stack that goes to the roof through a 3x3x3 comb wye and 1/8 bend.

Can I legally do a similar connection to the 3” vent in the new loft bathroom above? 2021 IPC.