I certainly don't think that Rontgen deserves to be forgotten.
I have bought all the symphonies and concertos so far issued on cd and will continue to do so.
Now that is partly, I will concede, because once I start to collect a composer's orchestral and choral music the 'completist' in me seizes control of my wallet

, but I am perfectly ready to assert that in his very conservative idiom Rontgen's music is not simply pleasant but gives genuine pleasure.
Whether he was "an enormously gifted composer" or "an absolute master of compositional technique" I am not qualified to say. He may well have been. For those who enjoy Rontgen's idiom I welcome the interest being shown in his music.
My gripe, I suppose, is that because Rontgen wrote so much, so many symphonies, so many concertos, the attention being lavished upon him and the commitment to record everything means that other composers' works (including those by other Dutch composers) will take longer to emerge. I hope that I am proved wrong and that CPO will press ahead with its promise to issue all the van Gilse, the Badings, the Pijper etc.