It would be expected that Tolkien would feel this way being that LOTR was released shortly after WW2 and the horror of Nazism and anti-semitism was still fresh in everybody's minds. If Tolkien is this familiar with Wagner's work (Wagner died in 1883 so Tolkien could not have known him personally), it is likely that he was a fan of Wagner's work.
That is not to cast any aspersions upon Tolkien. I have no doubt that Tolkien despised the man himself and what he stood for. Wagner was a rabid anti-semite and his works were supposedly embraced by Adolph Hitler and the Nazi party - though the extent to which that association is valid is a matter of debate. Frankly, I don't think Hitler and his Brownshirts spent a lot of time going to opera. It could simply be that Hitler admired Wagner for his beliefs and his music was secondary.
The author of this article points out a whole slew of similarities between Tolkien's LOTR and Wagner's Ring Cycle (an opera that takes three very long nights to perform). Though familiar with both, I had never before realized how similar the two works were (I mainly listen to the music and don't pay much attention to the librettos of Wagner's operas).
I read LOTR in high school, then in college I read Das Nibelungenlied for an advanced German class, and at that point I realized that both Tolkien and Wagner based their works on the same Norse epic. Wagner was a ferocious anti-Semite, Tolkien was anything but.