Yeah I suppose so, but that's from when the shovel hits the ground. Plenty of time and stuff to do before that happens in either place.
T-Mobile Arena was announced in 2013, broke ground in 2014, and finished in 2016. Little Ceasers was announced in 2013. Broke ground in Sept 2014 and Opened Sept 2016.
Not quite the same, but probably a bigger task. Climate Pledge Arena was signed into MoU for redevelopment (while having to retain historic aspects) in Dec 2017 and opened Oct 2021 even with the pandemic.
3 years is a quick timeline, but recent arenas have been announced and built in that timeframe in the States. Georgia is pretty friendly for it. Their last big stadium was MB Stadium for the Falcons (much larger scale). Announced in 2013, broke ground in 2014 opening in 2017.
IMO Houston and Atlanta will be the next two. Houston is fairly plug and play with some upgrades. Atlanta has two projects in the works and just needs the sign off on the right one to start. Probably happens this season. So ~4 years from that point is probably pretty safe.