I don't think that is the reason for the pump in altcoins. Especially in xrp, there is this even in xrp which is the spark token airdrop. We can see this as a reason for the increase in the price of xrp, it does not harm the price of bitcoin or even manipulated by the pumps of it.
People always come to conclusion, if there is growth with altcoins then it'll affect the growth of bitcoin. I don't find this to be true, because everytime the growth of altcoins takes place following the bitcoin price pumping. Maybe few top listed altcoins grow high even when there is decline in the market of bitcoin. This is based on the market of that particular altcoin. For this we can't correlate bitcoin market getting influenced by the altcoins price pumping.