Yes, because both statements are equivalent to the existence of an exact triangle of the form
$$W\longrightarrow X\oplus Y\oplus Z\longrightarrow V\longrightarrow\Sigma W.$$
The arrows are the same as in your diagram, except that you have to change of the sign of $W\rightarrow Y$ so that the first two arrows compose to $0$.
EDIT: The above 'answer' is shamely false. Let me just offer here a brief explanation of Jacob Lurie's correct answer. If the diagram is a homotopy colimit then we have an exact triangle
$$W\oplus W\stackrel{ \left(\begin{array}{cc} f&0\\ -g&g\\ 0&-h \end{array}\right) }\longrightarrow X\oplus Y\oplus Z\stackrel{(f',g',h')}\longrightarrow V\longrightarrow\Sigma W.$$$$W\oplus W\stackrel{ \left(\begin{array}{cc} f&0\\ -g&g\\ 0&-h \end{array}\right) }\longrightarrow X\oplus Y\oplus Z\stackrel{(f',g',h')}\longrightarrow V\longrightarrow\Sigma(W\oplus W).$$
The homotopy limit condition gives rise to an exact triangle of the form
$$W\stackrel{ \left(\begin{array}{c} f\\ g\\ h \end{array}\right) }\longrightarrow X\oplus Y\oplus Z\stackrel{\left(\begin{array}{cc} f'&-g'&0\\ 0&g'&-h' \end{array}\right)}\longrightarrow V\oplus V\longrightarrow\Sigma W.$$
If $W=X=Y=0$ then you get an exact triangle by putting $V=Z$ and $h'=1_Z$ $$0\longrightarrow Z\stackrel{1}\longrightarrow Z\longrightarrow 0$$
But if you put $X=Y=0$, $V=Z$, and $h'=1_Z$, then $W=\Sigma^{-1}Z$ since the exact triangle is
$$\Sigma^{-1}Z\stackrel{0}\longrightarrow Z\stackrel{\binom{0}{1}}\longrightarrow Z\oplus Z\stackrel{(1,0)}\longrightarrow Z.$$