Trouble pronouncing monosyllabic words with tripthongs

Hola a todos,

I have a question I’d like some clarification on from native speakers from Spain, as it mostly has to do with «vosotros» conjugations.

I was recently reading about the 2010 spelling reform changes instituted by the RAE, and I understand a number of them concern words that previously were bisyllabic (pronounced con hiato) and thus were written with a tilde, but now are monosyllabic (pronounced con diptongo o triptongo) and therefore have had their tilde removed to better reflect their pronunciation.

Words include: - «guion» (prev «guión») - «truhan» (prev «truhán») - indicative first-person singular preterite «hui» (prev «huí») - indicative second-person plural present «huis» (prev «huís»)

Additionally, the verbs «guiar» and «criar» were handed analogous spelling changes for the same reason. The change affected their indicative first-person singular preterite and indicative third-person singular preterite conjugations, as well as their second-person plural present conjugations in both the indicative and subjunctive moods. «Reír» also received equivalent changes, but only in the indicative third-person singular preterite and the subjunctive second-person plural present.

Now, most of these changes make sense to me; I have no problem pronouncing «guio», «crie», «rio», etc. as monosyllables with diphthongs. However, I just cannot find a way to pronounce the second-person plural conjugations of these words in only one syllable—«riais», «crieis», «criais», «guieis», and «guiais»—and even have a hard time imagining what they should sound like.

Every auto-generated pronunciation I can find online of these words pronounces them with 2 syllables (e.g. /ɡi'ai̯s/ and /kɾi'ei̯s/ for «guiais» and «crieis») even though the RAE and Wiktionary both indicate they are pronounced /'ɡjai̯s/ and /'kɾjei̯s/, with tripthongs.

Are these actually pronounced as monosyllables in Spain (and if so, can you point to an example of one being spoken aloud) or is this just an example of the RAE being overly-prescriptionist?