It's well understood that Spellcasting in a creature's stat block is a class feature. For the purposes of Change Shape and similar abilities where the term "class features" has mechanical importance, are there any other class features in official monster stat blocks? The wording in Monster Manual implies that such things could exist, but do they, and if so how do we tell?

Examples of creature stat blocks with named abilities that might be class features (vs classes where an equivalent ability is a class feature):

• Kobold Scale Sorcerer's Sorcery Points vs Sorcerer?
• Would a shape changed Couatl be able to sorcerize its innate spells?
• Drow Shadowblade's Shadow Step vs Shadow Monk?
• Firenewt Warlock's Imix's Blessing vs Fiend Warlock's Dark One's Blessing?
• Githzerai Anarch's Psionic Defense and Unarmed Strike vs Monk? (I don't think we're in class feature any more.)
• NPC Assassin's Assassinate, Evasion, and Sneak Attack vs Assassin Rogue?