@Mary419,
How did you come upon this information? Would you please share if this was an email sent to you from Airbnb, or the link to an online post from Airbnb? I think it's not an official announcement.
I am asking for this, because the message isn't written with American English spelling and grammar (assuming that your account is in the US based upon the location of your listings) e.g., honour instead of honor, and the word guests is not capitalize but says Hosts. Also, in US English, the term "for example" is always the start of a sentence and is written after the period (full stop) of the preceding sentence like this, "For example,". Lastly, another red flags, is that it says "72** hours". This is not how any English grammar is written to denote the amount of hours. I'll also that it says the change will become in effect next month instead of a specific date, and Airbnb always states a date for a policy (new or update) implemented. This is required to allow hosts an opportunity to opt out, if they so choose.