No, I think all the wives mentioned died, although I believe that Leonard did have one child out of wedlock in May 1860 in Glasgow - named George.
I found Leonard's marriage to Jane McLaren at Woods in 1830 and the birth of a daughter Mary abt 1830 who is not on the 1841 Scottish census. In 1841, we have John born Ireland and David, James and William born Scotland. I don't find John or David's births, but at death, they give their parents as Leonard Watterson and Jane McLaren. James' death is a mystery but he may have died at sea near Montreal so didn't find parents' names. William is not on the 1851 census but John, David and James are. Jane McLaren dies Feb 29, 1856, and Leonard remarried July 21, 1856 to Jane Beattie who dies Sept 19, 1859 after having sons William and Joseph, and Leonard remarried to Rachel Watterson Nov 3, 1860, and on the 1861 census, we have Leonard and Rachel with sons Leonard age 8 and William age 3 so son Leonard must belong to Jane McLaren whereas William belongs to Jane Beattie. I don't know what became of 10 day old Joseph when Jane Beattie died. Rachel had Mary Ann in 1861 and Richard in 1863 before dying May 4, 1869.
Then did Leonard go back to Ireland and marry Jane Blair in August 1869 ??. I don't find Leonard in Scotland in 1871 or 1881 but he is with his son Richard when Richard died in 1878 in Glasgow. I don't know what became of Mary Ann born 1861. So there is room for Leonard to have married Jane Blair but what then became of Jane Blair?
John is on the 1881 Glasgow census with brothers Leonard and William tying the brothers together.
It is strange that when Leonard died in 1886 at the same address as son John lived at in 1881, and John is the informant, John names Leonard wives as firstly Mary Rae, secondly Rachel Watterson, and thirdly Jane Robinson- What about his own mother??? I can't find Mary Rae and Jane Robinson in connection with Leonard at any time, unless they were "common law" marriages.