Does the IP address over a mobile data connection (gprs, 3g/4g) change every time on new connection?
The answer is this varies by carrier and can vary for any number of other circumstances such as market, locale, and traffic density... Both answers you referenced are correct for certain situations. I have also seen DHCP leases in crowded mobile network areas be under 4 hours... So does your IP address change every time you connect? Sometimes it will, sometimes it won't, there is no definite answer that encompasses all/most situations.