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It's poor design to make an unskippable message, in most cases. Some players naturally read faster than others and won't be willing to wait.
For that reason, I've never looked for a message that forces the player to wait for the text to appear, so I'm not familiar with one. If there isn't one by default, you might want to look into a script.
(wora's scriptMIGHT have this feature, if not you might have to request it. his is the only message system for VX that i know of)