Unlike the EliteBook xx0 or ProBook xx0 series, the alternative xx5 series is equipped with AMD options that are typically less expensive than the standard Intel offerings. All of the new models will carry the same Ryzen 3 PRO 2300U to Ryzen 7 PRO 2700U APUs and integrated Vega graphics. The updated systems will succeed the poorly-received Bristol Ridge APUs as found on the EliteBooks and ProBooks of yesteryear.
https://www.notebookcheck.net/HP-EliteBook-735-745-755-G5-and-ProBook-645-G4-launching-this-month-with-AMD-Ryzen-PRO.303074.0.html
Sadly, no Thunderbolt. The 745 G5 datasheet spells it out in the "Messaging Footnotes"
Quote2 Thunderbolt not supported on 700 series only supports USB-C.
Well, since Thunderbolt is (at least until very recently) tied to royalties to the great overlords from Intel, I don't think it's surprising to not see it on these notebooks.
However, shame on HP for putting so damn dim displays in these, and for providing no pointing stick in the ProBook model.