I run several groups. There's force users in all groups. Even though there are some that wish to learn the path of the Jedi, Yoda's statement could still be held true*. Luke could be the "last of the Jedi" in that he is the only one Yoda recognizes as a Jedi.
Second thought is that Luke was the "last of the Jedi" because the galaxy needs him to believe in himself so that he can defeat Vader & the Emperor, so Yoda told him what he needed to hear.
Third thought is that Yoda's connection to other Jedi across the galaxy, as shown in Star Wars Rebels, was only when those Jedi were also in Vergences like Yoda, such as the Lothal Jedi Temple. We have no evidence that he can sense or communicate with those individuals at any other time as his connection to them seems to be non-existant otherwise. If he never comes into contact with them again, it's very possible that he would believe they are no longer around.
The fourth thought would be that they renounce being Jedi at some point and most player characters tend to want to do their own thing, very few wanting to follow the strict path that Jedi take.
The fifth would be that yes, those people are dead or maybe presumed dead.
*From a certain point of view
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