Not necessarily, but a hammer arrestor is only needed where you have fast acting valves - like the icemaker, washing machine, etc. A hammer occurs when the moving water is quickly turned off and the inertia tries to keep moving. Having an air chamber buffer helps absorb that energy.
Now, as to what you had...it was probably useless after a couple of months. The moving water eventually will absorb all of the air, and then that pipe was nearly useless until the next time your drained the pipes. A proper hammer arrestor has a sealed air chamber. Different brands do it different ways. The chamber can compress, but it doesn't touch the water, so the air does not get dissolved in the water...it lasts much longer.