Actually, it was Roberts that didn’t sign with the majority not Thomas.
I took time to read it myself. I now agree with you.
https://www.supremecourt.gov/opinions/21pdf/19-1392_6j37.pdf
P. 8 (of the pdf file) says "ALITO, J., delivered the opinion of the Court, in which THOMAS, GORSUCH, KAVANAUGH, and BARRETT, JJ., joined. THOMAS, J., and KAVANAUGH, J., filed concurring opinions. ROBERTS, C. J., filed an opinion concurring in the judgment. BREYER, SOTOMAYOR, and KAGAN, JJ., filed a dissenting opinion." That's 6 for overturning Roe, but Roberts (as part of the 6) didn't sign the majority opinion.
Thomas' opinion p. 117. He wrote a lot about "substantial due process" being a made-up construct, that only due process is a constitutional right. Basically, he said quit making up "rights" out of thin air.
Kavanaugh p. 124. He wrote against the view that some pro-lifers have that the Constitution has a right to life. Like Thomas and the others in the majority he's saying that abortion is a states' rights issue. Unlike Thomas, instead of worrying about the left using "substantial due process", he seemed to worry about the right saying the Constitution guarantees pro-life.
Roberts p. 136. He concurred (making it 6 justices for overturning Roe) but added much language saying he supports states blocking abortion a little, as long as they allow it within a reasonable timeframe (maybe 1st trimester). So technically he's a 6th justice for overturning Roe, but he wrote a bunch of pro-choice language.
The 3 dissenters on p. 148 (Breyer, Sotomayor, and Kagan).