If you ask me, this is unlikely. Really, if they don't cash out when Bitcoin price is over 900 dollars per coin and don't want fiat, why would they want some junk altcoins? It seems to be a common opinion that cryptowhales hold their bitcoins waiting to become super rich in the future, and they have already written fiat money off in their mind, so would they even think about alts in that case?
the whale traders (not holders) will ride btc up and at some stage put aportion into alts. if alts go on a tear the returns go 10 - 100x - see litecoins $2 - $50 or ETH before the DAO.
You talk about whales, though you actually mean some small traders with a few bitcoins at most. Whales hold thousands of bitcoins, and investing in altcoins big time involves an insane amount of risk for them and their finances, while investing small is simply not worth their time. If they can steadily and safely make a percentage or two with Bitcoin, as you seem to assume, it doesn't look very plausible they will be interested in anything else.