no it doesnt. because if enemy uses srh, he targets his own monster not yours. i use srh very often and faced rare metalmorph sometimes, in the end rare metalmorph didnt prevent enemies monsters from beeing destroyed.
Since when has this card been able to negate the effects of monsters, I used armored dragon lvl 5's effect to destroy an ancient gear beast and my opponent activated rare metal morph and negated the the effect no lighting went around the card to show that the effect had been negated either
Not a bug: at the time Rare Metalmorph's effect resolves, the Spell you chained to hasn't resolved yet. So, Rare Metalmorph has only 1 resolved Spell effect to negate: that of the Spell card already equipped to that monster.