I agree with the term "Laudative" being apparently the correct term for referring to a commendatory grammatical term. It's in fairly regular current use in that sense in linguistic circles, even if you filter out French results, and anyway it just makes intuitive sense from the word laud. Google n-grams shows slowly increasing usage since the 1940s.
However, there are plenty of terms that could be used if you wanted to avoid the OED's incorrect categorization of it as "obsolete", rather than as "jargon".
While these words mostly aren't specifically nouns to describe grammatical terms, I'd generally use one of:
- a commendation/a commendatory term/a commendative.
Cambridge dictionary lists commendative only as an adjective synonymous with commendatory, and defines commendation as: "praise, or an official statement that praises someone"; "an honor such as a prize given to someone because they have done something that people admire"; "a formal statement of praise for someone who has done something admirable." Commendative seems very rarely seen.
Given these, these terms can carry implications of formal, official or public recognition.
- an approbation/an approbatory term/an approbative.
Cambridge again defines approbative as an adjectival form of approbation, rather than as a noun, and approbation as "approval or agreement, often given by an official group".
The term approbation also isn't super well known, and to those unfamiliar with it, can even appear to mean something negative. It also has the same problems as commendation in that it can imply formal recognition.
However, approbative seems at least somewhat more common than commendative and laudative, though it is hard to tell how much, if any of this usage is in the grammar-jargon noun sense rather than the lay-speech adjectival sense.
Relevant Google Ngram.
- a praise/a term of praise
This seems the most direct, simplest term. It's vagueness makes it ambiguous whether you mean the whole statement rather than a single word, so you might have to use a compound like "a praise-word" or "a term of praise". There's also the possible misinterpretation as having religious overtones.
I can find only a very few usages (one, two) of the term praiseword in this jargon sense, and it is not referenced in any online dictionary I could find, but honestly, as an antonym for curseword, it may well be way more intuitive and suitable than the more technically correct laudative, for non-jargon contexts like the linked articles.