False analogy.
If I tell you that I'm bringing apple slices to the potluck like I do every year, but I'm also bringing brownies, then you can't claim I'm not really bringing apple slices just because everyone will want the brownies and won't eat the apple slices. I brought them, I said I would bring them, it is your choice to eat them or not.
I literally just gave the same example, only you switched it to food. If everyone wants chocolate, so you bring both apples and chocolate (in this case you should have just dipped the apples in a chocolate coating

) to the party. You know everyone will choose brownies because they have chocolate. A real testament would be for you to say, "I brought two trays of brownies because that is what the majority are going to want." or "I brought brownies and chocolate covered apples because I know everyone wants chocolate." That is a choice.
Just like my example, it is clearly not a choice - even though it is. In my example, the DM might say, there is a chance you can sneak by the dragon and find something really interesting. That is an actual choice. But to present two champions, two assassins, two way of shadows knowing full well no one will choose the 2014 version is not a choice. Hence, this choice actually becomes a non-choice.
You can mix old with new. There is no barrier to doing so. It doesn't matter that the new stuff is stronger, because you can still mix the old with the new, exactly like they said. They aren't liars just because people will want to play the fixed version of the characters.
So, I never once, ever, in this entire thread called them liars. My position is, some people are upset because they wished they had been more forthcoming, which some deem as honesty. And some people wish their initial call-out of this choice being not really a choice, should be acknowledged.
They constantly said they were improving the classes, making them better than ever. They never once said that there is no way you will want to use the old version, they never once said anything about the old version except that you can still use it if you want to.
Which is 100% true.
If you keep looking at 2024 and thinking "there is no way I would ever want to use a 2014 version of this" then... they did a great job? There is literally nothing wrong with that at all. It doesn't break their promise in the slightest. Because all they promised was that you COULD use the old version. And you can. And many people WILL, because they HATE the 2024 versions of the rules. I have a player who is currently taking the stance that they will never play a 2024 paladin and will only play a 2014 paladin. And they can. It will still work. I think they are making a poor choice, but it IS a choice.
I never wrote that they said the bolded words. Those are fiction. Please re-read my post. Those quotes are what some people want out of a company. (And I said it will never happen.)
Look, they don't have to sell it to me. I am already sold. We are starting our new campaign, and to be truthful, I am a bit bummed that our DM doesn't want to use the new stuff. (He wants to wait until there is more published material for it, which is more than fair.)
Lastly, your player using the old paladin is a good example of what players want - stronger characters. Once someone finds some new combo where the paladin can multi-class with the sorcerer and they can now do more damage than the 2014 paladin, he'll probably go all in on the new paladin. (I mean, if his stance is he'll never play the new paladin because of the power level.) So, if you make 40 subclasses, and 38 of those are stronger, guess which way the wind will blow? And that is a good thing, except it might not be for many individual players and DMs. But they must move with the herd if they wish to keep playing with their group.