Even Sony's estimates now believe that the Switch 2 will outsell it and looking at how April went and how May is shaping up to be, I think Sony's predictions are optimistic.
Let's suppose that GTA 6 won't start to significantly interfere with PS5 sales until October, since it launches at the second half of november. And that PS5 sales will have a bump in September due to Wolverine
That leaves us 5 months of PS5 selling around half a million per month if the trend continues to follow April. And May is showing that sales could go even bellow that.
So that leaves us 7 months to sell 12,5 million. Which is possible, but highly unlikely, considering the trend.