I feel like he will only be top/mid. If you look at the current ap junglers:
Maokai (builds tank, has target cc, some sustain, AOE)
Fiddlesticks (lots of sustain, nice aoe ult, works really well with zhonyas for some tankiness)
Elise (is considered trash but she has good cc, builds tanky while getting some damage, has sustain with spider w, 6 abilities)
Eve (evelynn has that amazing jungle pressure passive, AOE)
Gragas (builds tank, amazing cc, good sustain, AOE)
Malphite (builds tank, has good cc with a bit of sustain from passive, AOE)
Nautilis (builds tank, amazing cc, some sustain with shield, AOE)
Nunu (consume pressure, builds tanky, has good buff for adc, sustain)
Rammus (builds tanky, pretty good cc, aoe)
Sejuani (builds tanky, good cc, aoe)
Diana (good aoe, becomes a threat later on)
Ekko doesn't have good AOE damage for the camps. Also, he has minimal sustain. His shield is only up for 2 seconds which gives him mimimal sustain. Furthermore, his ganks are pretty mediocre and he doesn't have the power to power farm. Since he doesn't build tanky, have much sustain, or good AOE, he wont really be played in the jungle. The closest jungler to him would be diana, and she is played mid far more than jungle, plus she gets a bigger shield + better waveclear