NPL was definitely doing work there in 2023. Here's the street view of that exact location in 2023.
View attachment 671064
The existing gas main is on the south side of Duke. NPL was working along the north side of Duke (just out of frame is the directional drill with the shot going up towards the hydrovac truck at the tracks). I don't know if the main on the south side is still active or not after what NPL previously did.
The only possible reason I could see the need to touch those gas mains again is if the existing gas mains need to be removed/lowered. In the plans for the future transit hub (KCTH) the grade of Duke drops to accommodate the MUT tunnel under the tracks which is located on the north side (opposite from the gas main). The other thing is there will be a retaining wall running between the tracks and the bus loop access road (if I recall it extends all the way from King St to Duke). It is certainly possible that through the detailed design process it was discovered that the main was in the way and now they have to move it especially with work starting to pick up on the transit hub. The Region has completed the pre qualification process for the demolition of the non historical parts of the Rumpel Felt building (the reddish/brown building), with that expected to occur later this year once the RFT is procured.