I would consider that if you see that, it's really more just simple immaturity in general in the area of growth and development, and not a characteristic of mystics in general. The mystical experience itself can be quite humbling, to say the least. As they say, the more you know, the more you know you don't know.
But to your point if someone is insecure in themselves on a personal level they may seek for validation from others, and if it's lacking they may overcompensate and think of themselves as more enlightened than other mystics, claiming they have the truth!, or that they are the grandmaster-level-10 black-belt mystic and all others are but junior mystics compared to them, and so forth. All that of course has to do with the ego and not how deep or how far someone goes in mystical states.
How far someone can go in mystical states is not the measure of their maturity as far as ego development, let alone "overcoming" the gravitational force of ego goes. It's kind of like saying that so and so is the greatest athlete in the world, therefore he's the most humble and wise person alive.
Does it really mean that? This is actually one of the sneaker and trickier parts of mystical experience you don't mention. The ability to deceive ourselves we have truly grown just because we can enter into the deepest states of meditation for prolonged and sustained periods.
It becomes actually far more insidious, sneakier ego hiding out as we think our "achievements" in mystical experience translates into we have now truly arrived, that we've reached the final layer of that ego-onion we've finally 'overcome'. We confuse development in one area with development in another. In reality, each stage of our growth has its shadow. Each stage has it's potential pathology. To me, it's better to be aware that we never arrive, than to start imagining we are at some imagined level and assume everything else is somehow fixed, that we're now "beyond all that". That's where the beginning of Wisdom finally has a chance with us.