IRST was also one of the expectations of the Block III. But it's not a critical capability.
I don't want to offend anyone ... No it was not in the same way the swept tail was not and so on! It was expected by some fan-boys, which forgot that the new tail was added due to the new front section. As such with still being a single seater, there was no need - and even more quite to the contrary - no reason for the swept tail.
But as I and several other reliable and reasonable ones expected - and it is not to mock anyone: I said since months, all fans will be disappointed, who expected a semi-stealthy larger, wider, bigger, and so on aircraft. It is more or less the same and the changes are mostly under the skin.