Desis in 1850's
Desis in 1930's
Not all, but many desis in the 1960's and 1970's
If all of the above is possible, as time passes, then why isn't living together possible? It will soon become common too. Maybe it's considered a taboo by desis, but in about 20 years probably not.
For desis who put their "culture" over "religion", then yes, maybe with time it will become very normal and acceptable for a guy and girl to have a relationship and live together before marriage. For desis who put their "religion" before "culture", no it wont be, because it is clearly haram in Islam and time doesnt change that. Things you are mentioning being taboo in the past and then changing (like love marriages, talking on phone with suitor) are not even haram in Islam, if done properly and within guidelines, so you cant compare living with someone (and sleeping with, Im assuming thats what your post is about, not just being "flatmates") to talking on the phone with someone