Well, this whole text is subtly pejorative, suggesting that tp as it is used is somehow incorrect, while the version that exists only in textbooks is the real deal. Typical prescriptivist claptrap. And ignoring that the textbooks themselves don't even use the language they describe.
As for the name used in the title, it is simply inappropriate. Esperantido was a topdown conscious revision of Esperanto, led by a band of prominent Esperantists with a list of changes they wanted enforced on all other Esperantists, a coup, in short. What we have here, if anything, is users of the language developing in that use forms that differ from what the textbooks say (an often in areas where the textbook does not speak at all). Evolution, then, since it arises in and from living and is mostly unconscious.
So, i suggest that we call this language simply "toki pona" or, if we politely allow the textbook language a courtesy connection with that name, "toki pona lon". The textbook language is then "toki pona pu" or "toki pona Pije" depending on which version is set up as exemplar.
it is ultimately unclear what the fuss is about. The big differences seem to be whether or not to use 'e' with 'kepeken' and to use 'pi' with prepositional phrases modifying nouns (pu and Pije disagree on the first and neither discusses nor exemplifies the second, except by implication from a rule that neither actually uses). The difference seems to be about whether or not the language needs topdown control. But tp doesn't have even the rather loose sort of control that Eo has. Nor does it need it, since, unlike Lojban, rigorous adherence to an exacting standard is not required for its purpose, which is intelligibility, not monoparsing.
On the whole, simply acknowledging that there are dialects and setting out their parasmeters seems the sensible thing to do to hold the language community together. And, of course, not casting aspersion on a fellow tper whose dialect (even idilect) is different from youur own.