There is no doubt that the main presenter will be Alessandro Cattelan, especially now that he is a RAI employee. Considering that he has been kept out of the next edition of Sanremo, the chances of him trying his hand at Eurovision are practically 100%. RAI doesn't have another name as good as his if we have to look for a dynamic face, already used to musical events and able to speak English.
It's weird for me to read Chiara Ferragni's name because she is not a presenter (I know it is not a requirement for Eurovision but still...) and especially because her husband Fedez has been fighting with RAI for a few months, so I think it is unlikely she will be chosen by the broadcaster for such an important event.