Because of the "modular" system in the name I would assume they want something like a weapon such as the CZ-75B and Kadett kit. (not necessarily that particular combination, but that idea...swap out the barrel, slide and mag, and you have a different caliber pistol.
High Standard did that with their upper end pistols years ago, except it was 22lr coversion to 22 short or VV. High Standard did also make a 1911 that was convertable to 22lr. Brownells has the 22 short conversion kits still available, but they are really pricey...really happy I already own one, would not wont to have to purchase one now.
I could conceive of a pistol being developed that could fire all 4 of your choices, and maybe 22lr too. That would be a true "modular system"