If I understood correctly, then that sounds a bit like a UI issue.
The host should never be able to change the dates. I mean, why should they be able to? It's up to the traveller to decide when the stay should take place and the host can either accept or decline.
Agreed. I made a change to the dates of a stay earlier this year (cottage booked on Isle of Skye in the UK). I needed to shift the dates forward by a day or two. This was easily accomplished in the website UI, no direct contact with the host was required. Not sure why the host would ever be able to change booking dates, or really make any changes to the booking after it's confirmed.
The host should never be able to change the dates. I mean, why should they be able to? It's up to the traveller to decide when the stay should take place and the host can either accept or decline.