Matthew 24:3 and it's Parallels

(Matthew 24:3) . . .While he was sitting upon the Mount of Olives, the disciples approached him privately, saying: “Tell us, When will these things be, and what will be the sign of your Parousia and of the end of the age?”

(Luke 21:7) . . .Then they questioned him, saying: “Teacher, when will these things actually be, and what will be the sign when these things are destined to occur?”

(Mark 13:4) . . .Tell us, When will these things be, and what will be the sign when all these things are destined to come to a conclusion?”

The phrases highlighted in red are exact parallels and specific questions related to the temple (in context). The word highlighted in purple, refers to a sign that would occur before the destruction of the temple in Luke and Mark. The same cannot be said for Matthew for he adds "Parousia" to his material that Luke and Mark don't. Could it be that Luke and Mark are interested in the Temple's destruction but Matthew interested in more than that? I can't say for sure, but that would be my opinion. 

Further, in Luke and Mark they specifically ask again when "these things" (highlighted in orange) would happen. Matthew doesn't add this second, "these things." Rather, he adds instead "the end of the age." I don't believe "the end of the age" is a different way of asking when "these things" would happen. For it if does, then the end of the age happened in 70CE and we are left with unresurrected loved ones and without a restored earth.