In early rose references, there are many cases of hybrid roses with China ancestry being referred to as Hybrid Chinas or Hybrides de Bengales. Breeders of the early 19th century tried crossing many kinds of roses with China roses in hopes of producing roses that rebloomed, and 'Hybrid China'/ 'Hybride de Bengale' was often meant very literally, and did not yet refer to the once-blooming gallica x China hybrids that we now use those phrases for.

Keeping this in mind, it seems likely that 'Ayez' could be both a Hybrid Sempervirens *and* a Hybrid China. In the same way, a number of Boursault roses were also described as Hybrid Chinas, and I think Laffay's 'Amadis' is a good example of where we have one rose with two different records because of our modern notions of what 'Hybrid China' means. Similarly, some early references refer to Tea varieties as hybrid Chinas.

I am agnostic about whether 'Ayez' is a synonym of 'Spectabile', but I think it's quite likely that they both have Sempervirens and China ancestors.