Yes, most likely, but the justification for it happening in Japanese parlance is still relevant. For a corner joseki to be "accepted", and for example, to end up in Ishida, as you say it would be expected to have passed up-to-date scrutiny of professional Go players.

However, to stretch the analogy slightly, joseki can have a very subjective usage too. If I always open on diagonal 4-4s and then respond with a low close pincer to a kakari, I could describe my behaviour as adhering to joseki from a personal perspective. Even though it has a specific usage with regards to acceptable corner sequences, it isn't the precise meaning of the word itself, just its typical application in Go terms. As such, to tell an amateur they are misusing it may be too strong a chastisement.

CAVEAT: Although Kageyama also touches on exactly this in fundamentals, I am getting this second hand from a Japanese amateur player who I had this exact fun discussion with, and so my interpretation may not be completely accurate.

Can you say any pro game, which ended with 1/2 points difference, I mean the complete kifu, is joseki?

_________________
If you say no, Elwood and I will come here for breakfast, lunch, and dinner every day of the week.

How many times must a sequence be played
Before it becomes joseki?
I feel in my bones
It's under the stones.
The answer is under the stones.

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The Adkins Principle:
At some point, doesn't thinking have to go on?
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Visualize whirled peas.

Everything with love. Stay safe.

The answer is 42.

Actually my own, personal, opinion is that we have to make our own decisions as to whether a sequence of moves is "joseki" for us. That's what pros do, I think. They have a much stronger grasp of positional judgement, etc., so their judgements are closer to whatever absolute correctness there may be, but they are still judgements. The thing is, if we toss out the dictionaries, databases and pro game records and only use our own judgements, it might take a very long time before our "mistaken" judgements get corrected. Studying the results of pro analysis of move sequences and understanding why they make the judgements they do can be very helpful in developing our own powers of evaluation

Which leads to an interesting question: What's the longest sequence played by more than one pair of pros? (To be technical, We could say we require all four of the players to be different, and say two sequences are the same if all stones played prior to the sequence in the "smallest rectangle containing all moves in the sequence" were the same in both games, for example.)

All those criticizing the poster seem to have missed the point. I doubt the poster is interested in memorizing these long sequences. They're more of a curiosity. Another variant of the question: what's the longest sequence that is (more or less) forced? That is, that all pros (or maybe 95% of them) play in a given situation (which maybe we require to have come up at least 10 times or so).

Read about a slightly different approach here: http://senseis.xmp.net/?WidestPath

Oh, I get it, Blowing in the Wind.

... why do I suddenly feel old...