Hi Mike,
EFI was an Intel initiative linked to the appearance of the GUID partitioning scheme. Almost all Linux systems today that use grub can boot from GUID partitions, so it's essentially a dead issue for security concerns as long as you run Linux. Microsoft was actually well behind and not ahead of the curve here as is almost always the case with them, but once involved they of course deployed their own little info gathering quirks to OEM EFI implementations that often irritate the Linux community in general.
"With the release of Windows 8 in October 2012, Microsoft's certification requirements now require that computers include firmware that implements the UEFI specification. Furthermore, if the computer supports the "
Connected Standby" feature of Windows 8 (which allows devices to have power management comparable to
smartphones, with an almost instantaneous return from standby mode), then the firmware is not permitted to contain a Compatibility Support Module (CSM). As such, systems that support Connected Standby are incapable of booting Legacy BIOS operating systems." (The caveat here is of course that any Linux with grub can boot from GUID partitions and could since 2000 if the code exists for the processor initialization)
https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_InterfaceTo answer your question, if the new computers are using Intel family processors and come with Ubuntu they will certainly be using UEFI. The MBR partitioning scheme is over 40 years old now.
PS: Also the reason the OEM Linux machines from Dell cost more is because MS machines are produced via a corporate partnership that shares costs. In this case free Ubuntu shares no manufacturing expenses with Dell.
TC