You have the same rights as other employees to be TUPE'd across. This means on the same conditions of your current employment and with length of service (time) with your existing company (OLDCO) transferred to the new one (NEWCO) - as if you had always worked there.
There would not normally be a good reason to want to resign and re-start your employment - unless the new company were offering you (significantly) enhanced employment conditions to do so. The issue is usually the other way around - employees TUPE'd across from OLDCO are often on better terms and conditions than existing (or newly recruited) employees of NEWCO.
The only difference between you and other long service employees of OLDCO is that because you haven't been there for over 12 months, in the event of your contract being terminated, you have no rights to claim for unfair dismissal at an ET - except for reasons associated with certain grounds like religuous discrimination, TU-membership or pregnency. These examples are standard get-outs in employement law, when the need for 12 months continuous employment do not apply.