If BTC makes an extended bull run I'm sure ETH will follow. But it's going to take a decent period of investor confidence to drive it.
From what I recall almost all crypto jump on the bull run bandwagon and see their value go up. I have no reason to doubt ETH, XRP and others will not follow - on the contrary I think they will follow suit. It has been some time since the last bull run so maybe BTC will break its all time high, I hope so

With all the hype of the ETH upgrade it will be interesting to see how it would affect its price over the next few months. I am not seeing anything major going on with it right now but investors are not rushing in to buy it even with the hype. Maybe it needs time to settle before investors start buying but the disparity between its all time high price to current price seem excessive therefore in my opinion ETH is undervalued.