While I do not expect to see Android devices with future Snapdragon 8 Gen 4 chipsets immediately booting mainline kernels on release, this might be a step towards achieving something closer to that. Those efforts will certainly make it easier for phone manufacturers to release updated kernels, and therefore Android releases, for their devices, or at least stop using Qualcomm as the excuse for not doing so (see e.g. Fairphone 4's software support roadmap: https://support.fairphone.com/hc/en-us/articles/9979180437393-Fairphone-OS).
I'm cautiously optimistic about this, because Qualcomm has been actually putting in some work to get the mainline Linux kernel more supported on their Snapdragon X Elite laptop CPU: https://www.tomshardware.com/software/linux/qualcomm-goes-where-apple-wont-readies-official-linux-support-for-snapdragon-x-elite. This doesn't necessarily mean the same benefits will come to their mobile chipsets, but I'm hopeful that there is some runoff benefit from their new laptop efforts here.
While I do not expect to see Android devices with future Snapdragon 8 Gen 4 chipsets immediately booting mainline kernels on release, this might be a step towards achieving something closer to that. Those efforts will certainly make it easier for phone manufacturers to release updated kernels, and therefore Android releases, for their devices, or at least stop using Qualcomm as the excuse for not doing so (see e.g. Fairphone 4's software support roadmap: https://support.fairphone.com/hc/en-us/articles/9979180437393-Fairphone-OS).