1. Not necessary. It depends on the subjects you are studying. Taxonomy journals might still publish your manuscript without the need of molecular data, as long as the finding is novel. Most reputable Scholar journals require manuscripts to be 'original' or 'with novelty' though (i. e. something new, not published before), even without containing molecular data.

See one of the examples w/o molecular data: http://www.europeanjournaloftaxonomy.eu/index.php/ejt/article/view/2942.

2. But you might encounter some editors and reviewers who specifically ask for molecular data to support your findings before publication.

Thank you sir

As for whether molecular data means more novel for Taxonomy study? You can find a discussion on this topic on RG. There are some good answers in the discussion.

Traditional Taxonomy vs. Molecular Taxonomy

https://www.researchgate.net/post/Traditional_Taxonomy_vs_Molecular_Taxonomy_Are_they_synergistic_or_controversial

If the morphological characters showing clear species character variations, that's enough. no need to go molecular level...

But, If the phenotypic characters having confusion, then only it is suggestible.

not necessary, i agree with chennakesavulu naik

Not necessary,If the motphological chacters are clearcut there is no point wasrting time and resources