If you follow the link youll see also ETH and all major alts are considered.
Yes, they were also considered. April is over, and we see that it managed to bring positive changes to many cryptocurrencies, including Bitcoin. I think it was bullish this month, surely.
April was the bullish month for the bitcoin only. It was indeed a worst month for altcoins as we see most of the altcoins went below their all time low value. No news or event like main net , listing could pump the altcoins for long time duration. Ask from the holders of altcoins and they will say that their portfolio are at extreme losses.