As of yesterday, April 1, Google began pushing out the April 2019 security patch.
This month's patch resolves your typical system framework bugs, in addition to patching a few things here and there with various Qualcomm components. Also, if you have a Pixel 3 or 3 XL, you'll notice improvements in voice unlock speed and a resolved bug that caused the screen to flash when exiting ambient display mode.
Looking through the AC forums, it would appear that a lot of people already have the update.
What about you? Do you have the April 2019 patch?