Upvote:1
First of all, let's discuss of what is "true" and how is defined.
From scientific point of view, the truth is defined by consensus of scientific community, so, until many sources (and documented ones!) agree on some definition, is not one single article the source of truth.
Authoritative sources (such as Wikipedia) clearly define the Renaissance period from 14th to 16th century, while the Romantic period at the end of the 18th century.
Second one, lets' read the text you quoted.
Right at the beginning of the text it says:
This is in some ways similar to the early Romantics. In both cases I also think they are definite 'reactions' to a rising dominant culture --Enlightenment then or scientific materialism now --which the Romantics stoutly reject as disturbing, unpleasant or inhumane.
Reading that, from the author point of view, it seems that Romantics (and early Romantic) is after Enlightment (17th to 18th century)
In the rest of the article the author only cite the correlation in one place (without any reference) as you have quoted:
It is arguable that the Romantics have had 4 major phases of expansion and flowering. The first was coincident with the Reformation and included the Italian artistic Renaissance - even though that was still mainly working with religious forms.
So, it contradicts himself (between the beginning and the quoted paragraph).
Given those two consideration, the answer to your question is:
Italian Renaissance can not be considered a phase of Romanticism
If - instead - we consider if the romantics have been inspired by their predecessor, and specially Italy's Renaissance, the answer is absolutely yes, and it is documented (as much as any other period takes from the predecessor).
On a personal note, by the article you quoted, we can see the Medieval Period as much Romantics as the Renaissance Period (take the "Roman de la Rose" as example)