Apple started fading out 3D Touch (pressure sensitive gesture) since the iPhone XR release in late 2018, so apps should start adopting Haptic Touch (hold and feel a feedback) everywhere. Not releasing the finger after previewing a sticker should show the context menu after a second, no matter the device you are using.
3D Touch still could be used for faster access in devices supporting it.
This is important to fix since users with a pressure sensitive screen may not be able to find the context menu for stickers since 3D Touch is a hidden feature in their phones (they don't know they need to apply pressure to the screen)
Steps to reproduce
On a device with a 3D Touch screen: iPhone 6s to XS (except XR)
Open the sticker panel and hold on a sticker (without pressing) to preview it
Keep holding your finger a bit more (without pressing)
Current result
Nothing happens
Expected result
Context menu for sticker is open
Device info
iPhones supporting 3D Touch (pressure sensitive screen):