You could ask Apple this directly. We had this question recently and a user chimed in saying that they apparently always replace the gasket for the seal as well, so it should be as water resistant as before.
They replace the adhesive for each repair. The liquid resistance remains the same, so like mentioned above, don't count on it.
Liquid resistance in iPhones (and phones in general) is the last line of defence for liquid damage.
Keep in mind, it is not just the adhesive under the screen. It is the adhesive around the loudspeaker, the earpiece, the mics. These adhesives age, wear and tear overtime from flexing the phone inside the pocket, heat from the sun, cold in the winter.