In my $.1, that doesn't necessarily mean much. Economic and social forces lead to similar results even when there's no specific communication between individual people. For example, if a song becomes a hit and makes millions to its producer, other producers will make similar songs because they too want to make a hit. If the king starts wearing a certain type of clothes, the courtiers will begin as well without anybody telling them to, and ultimately this will percolate to the general population. And so forth.
At the end of XIX/start of XX century, Okinawans were considered somewhat rural and rather second class in Japan, for a number of reasons (see for example
Between a Forgotten Colony and an Abandoned Prefecture: Okinawa’s Experience of Becoming Japanese in the Meiji and Taishō Eras - The Asia-Pacific Journal: Japan Focus ). What Funakoshi proved is that, as an Okinawan in Japan, one could have a relatively high degree of social and economic success by doing things in a certain way: adhering to the social context of the time, adapting to he established sport landscape, importing customs and practices from Japanese art and avoiding ruffling feathers by removing overlapping ones, promoting karate as way to fitness and a mean of instilling discipline and obedience to authority into young people and so on. Healthy, strong soldiers, used to line up, show respect to their master and obey his orders enthusiastically and without question.
Adapting is the key word. Funakoshi lesson was clear: to succeed you have to adapt, cut and sew again - something that probably was inspired by his own master which has done similar things in Okinawa, for a similar reason - remaining relevant in a changed context. And of course by the fact that karate had always changed, incorporating effective practices form elsewhere.
Funakoshi introduced karate to Japan in 1922. If not the first, he was the first doing it successfully and with a big impact. Moreover he was the first to successfully
make a living from karate. Okinawans weren't full time teachers. Even his masters had "proper jobs", so to say, or violence
was their job (as opposite to teaching). Perhaps without willing, he created single handedly the job of karate teacher. He had introduced one more, extremely effective change - only the effectiveness was not in unarmed combat (something which was socially quite irrelevant at that point and had been since his masters' time) but in making teaching karate a way to live and thrive.
Mabuni was born 20 years later than Funakoshi, lived in the same Japanese environment and created Shito-Ryu in 1931. He also happened to have the same master as Funakoshi. He is remembered as one of the first practitioners to teach in Japan. By then the same forces were even far stronger, and the "Funakoshi formula", so to say, was crystal clear. Funakoshi did not need to affect the Okinawans in Japan - they would have seen his success, and affected themselves. Incidentally, you can still see what happened to the few ones who did not. Choki Motobu is the classic example, and you can measure their successes by the size of the respective practitioners worldwide. Not many for Motobu-Ryu, so to say.
As for the Okinawans back in the islands, they weren't stupid: they saw what worked and the generations afterwards probably saw it even better - especially when a certain military base was established there and making money teaching karate to GIs became definitely a market (many of whom learned the lesson so well that they opened dojos once back home..). And when you need students to make a living, you give perspective students what they want - regardless of what the art is or is not (even assuming that, by then, you even remember). Because there's no making a living with actual unarmed combat. By the time Isshinryu was put together (late 40s) the formula had been around for a long, long time.
To this day, what's considered perhaps the most "different" karate style - kyokushin (pardon me the others) - is essentially a derivative of shotokan. Almost all the successful ones are, because that's what the initial market wanted, and karate spread mostly from that initial market, not Okinawa.
So while there may or may have not been throws in karate before Funakoshi (I am not sure, there's his 9 and more can be discerned here and there), what took them completely off the table were the adaptations that allowed many practitioners to live on teaching karate instead of using it in anger.
