. . . . . . . . her later shows (The Lucy-Desi Comedy Hour, The Lucy Show, Here's Lucy, & Life With Lucy) would have not come into existence either? If so, why?

I say no. I have no doubt she would have ended up on TV eventually, but not as the star. Probably in supporting roles like in all her movies.

Lucy probably would have done The Love Boat and Murder, She Wrote, like other washed up stars did during the 70's and 80's.

I don't think she'd have done those shows, but she'd still be a big television star. "My Favorite Husband" came to television in the mid-50's and she probably would have kept her role as Liz. So it's possible that after that show, she'd star in others.