I've got a P53 for work and I can think of a thousand reasons why this didn't pan out yet. One major problem is still updating your firmwares. While you can update your BIOS and "embedded controller" (https://fwupd.org/lvfs/search?value=p53), you miss out on firmware updates for your WWAN adapter, your Thunderbolt 3 docking station and several smaller things too. I suppose Lenovo's sales or whoever is in charge listens when the engineers tell them "you will have the following problems immediately, which we are not ready to solve yet". Would be nice if they actually delivered instead of promising, but I'm not mad at them for not rushing it.