Although you never want a champion vacating their title, it somewhat diminishes the value of the title, but 2 out of the 3 that vacated weren't in the grand scheme so bad. I'm talking about Askren and Konrad, who were dominate and would be champions for quite some times I believe, but their style wasn't entertaining. These champs were replaced by two far more exciting fighters in Minakov and Lima. I think losing Lombard was bad, because he was entertaining and was a draw for them. I think Askren and Konrad were superior fighters than Lombard, but I think him leaving was the one that hurt the most.
Bellator needs to be able to support their champions with lucrative contracts or they will continue to bolt for the UFC, where their can offer incentive laden contracts involving PPV cuts and better sponsorship money. It's not the end all be all if their champs leave, but it doesn't look good for the promotion. Viacom also needs to continue spending on stars and young talent, I think they'll be fine.