Intake manifold antifreeze leak

My mechanic replaced the exhaust gaskets on my Chevy Tahoe. At same tiime a "board" (?) Was replaced to resolve a blinker / tail light failure problem.

One week later my auto broke down. The same mechanic then replaced the alternator. He also questioned me about seeing any antifreeze under the vehicle and advised that I needed a new intake manifold gasket due to an antifreeze leak.
I had just observed signs of an antifreeze leak that started within days after the exhaust gaskets were replaced.

My question. In the process of replacing exhaust gaskets could the manifold have been disturbed to the extent that the antifreeze leak started? Any possible connection with the "board" beiing replaced and my altenator going out? Just seems strange that a second set of repairs would follow so closely to the first set.