I don't have a problem with the plans.
I think any solution that will make pilgrims safer during Hajj is welcome. I think any solution that will make it easier for Muslims to live in Medina and pray at the mosque of Rasoolullah is welcome.
I hope, though, that the tall buildings are not exclusively for the rich, or for the pilgrims. I would prefer to see those rooms occupied all year round, especially by residents. I mean, a traveller will go out of his way to pray at the Prophet's Mosque , because it's not something that he can do whenever he wants. But a resident might need to live close to it to take full advantage of the barakah.