Can the NPC Archdruid from Monsters of the Multiverse cast wildfire when using change shape?

Question

The new Mordenkainen Presents: Monsters of the Multiverse gives revised rules for many, many monsters, including the Archdruid (pg. 48).

The revised text for Change Shape says (inter alia)

While in a new form, the archdruid’s stat block is replaced by the stat block of that form, except the archdruid keeps its current hit points, its hit point maximum, this bonus action, its languages and ability to speak, and its Spellcasting action.

The Archdruid's Wildfire action is a ranged spell attack, but it is not listed under the "Spellcasting" options. Can an Arhcdruid use Wildfire while using Change Shape?

Answer 1

Wildfire is not a spell, so the Archdruid cannot use it while using Change Shape.

This is explained in the Sage Advice Compendium:

Is a spell attack a spell?

No. The game has two types of attacks—weapon attacks and spell attacks—so a spell attack is a type of attack, not a type of spell. Sometimes a spell attack is part of a spell, as in the fire bolt spell, but other times a spell attack occurs outside a spell, as in the specter’s Life Drain attack in the Monster Manual.

The Archdruid's Wildfire action is just like the specter's Life Drain attack referenced in this SAC question - it is a spell attack, but it is not a spell. And since it is not a spell, and not part of the Archdruid's Spellcasting trait, it loses the ability to use Wildfire while using Change Shape.

Answer 2

The Archdruid loses Wildfire

A ranged spell attack is not necessarily connected to Spellcasting at all. Take the Sun Soul Monk's (Sword Coast Adventurer's Guide) Radiant Sun Bolt for example:

You gain a new attack option that you can use with the Attack action. This special attack is a ranged spell attack with a range of 30 feet. You are proficient with it, and you add your Dexterity modifier to its attack and damage rolls. Its damage is radiant, and its damage die is a d4. This die changes as you gain monk levels, as shown in the Martial Arts column of the Monk table.

This is a ranged spell attack, but Monk's get no form of spellcasting and this is not a spell.

The spellcasting section in chapter 10 of the Player's Handbook states that:

Every spell has a level from 0 to 9.

Therefore, simply because it is a ranged spell attack, it is not considered a spell if it does not have a level from 0 to 9. Similarly, Wildfire is not listed as part of the Spellcasting action, and "Wildfire" is not a name possessed by any pre existing spell, it is being specifically created by this feature in the Archdruid's stat block.

Wildfire is an action that the Archdruid can use, and the only thing that "Ranged spell attack" means is that it is using it's spellcasting ability modifier in the calculation of said attack.

What this means is that the many "Spell-like" features in the new book are not spells, even though some of them mimic existing spells, if such a feature does not say "The creature casts X spell" then it is not a spell.