I would be with Uncle Bob (in “The Programmer’s Oath”) on this one:
“3 - I will produce, with each release, a quick, sure, and repeatable proof that every element of the code works as it should.”.
If the changes are generally well cover by non-business tests (unit, integration and component) and few bugs escape, one could postpone the “repeatable proof of work” to after the production code. Otherwise, for any reason, I would suggest that programmers take care of delivering them together with the prod code.
Additionally, I think that either way, it good to remember that timeboxed iterations are not micro-waterfalls: Each user story (or equivalent) should be independent - therefore, its validation should be wholly ASAP.
Leaving a number of independent stories being integrated without automatic validation for two weeks can be very risky - both functionally or in process (unsatisfied DoD), generating new tech debt.