you missed the part in Texas where it states ‘consent of the states’
succession is very possible and validated by Texas;
You’re talking about “dicta.” That was not a part of the holding in Texas v White.
The exact paragraph from the majority opinion that you are referring to says: “When, therefore, Texas became one of the United States, she entered into an indissoluble relation. All the obligations of perpetual union, and all the guaranties of republican government in the Union, attached at once to the State. The act which consummated her admission into the Union was something more than a compact; it was the incorporation of a new member into the political body. And it was final. The union between Texas and the other States was as complete, as perpetual, and as indissoluble as the union between the original States. There was no place for reconsideration or revocation, except through revolution or through consent of the States.”
Dicta: “Opinions of judges that do not embody the resolution or determination of the specific case before the court. Expressions in a court’s opinion that go beyond the facts before the court and therefore are individual views of the author of the opinion and not binding in subsequent cases as legal precedent.”
Holding: “Holdings, or ‘ratio decidendi’ (Latin for “the rationale for the decision), are those parts of a court’s opinion that are binding on lower courts and later courts.”
But don’t take my word for it. Here’s a link to the Texas V White Opinion, click on “opinion” to skip the syllabus.