Shaving method can leave some of the mole cells beneath the skin, and the mole may grow back again over the next several years.
Removing the mole can reduce the chances to get melanoma.
If the mole come back after several years it is expected to be normal not cancerous mole.
Melanoma can rise from a mole or normal skin area.
So, the mole that can come back, has the some potential to get cancerous as the other ones you already have on your body.
Anyhow, it's good to watch and check this site and all your moles every month by self checkups.