if crypto payments will be somehow popular in their store then they might become another big whale and in case of any financial crisis they may dump their coins.
Not all the merchants who are accepting bitcoins cannot become a whale unless otherwise they will do stash all their incoming transactions and compensating business with other income stream. You are talking a new whale as a negative thing, but they will help crypto markets to grow by saving cryptos in massive numbers.
Previously we could witness situations when some major ICO after successfull tokensale is selling its ETH. In this case they were dumping millions worth of ETH to the market and the price obviously dropped a bit.
How will they accept cryptocurrencies? Is that gonna be something like bitpay when you pay with BTC and a seller receives fiat or they are going to totally accept cryptocurrencies?
I am able to get your point but we are individual hence thinking like that but for a business point of view, I guess they might convert their crypto payments instantly into their local fiat hence there will be no bottleneck will be appearing just due to the introduction of new payment options. Accepting cryptos through a payment processor would be the first priority for any developed business as it will eliminate lots of hassles including withstanding against hard volatility of crypto markets.
Well, that was just my thoughts. I'm 100% sure that they won't have billion $ worth of BTC revenue so they probably won't become a new whale anyway.
But yes, making it easy to pay in crypto is an important step forward for crypto users.