When you say
〇〇店が入る雑居ビル
It can be interpreted 2 ways.
- 〇〇店 plan to set up a store in the building (future)
- 〇〇店 already have a store in the building (present)
The sentence itself is ambiguous. It can be mean the future or present. But you can distinguish one from another according to the context in most cases, as you did in the news program.
By the way, this is not a special case of verb 入る, but any verb works like this.
For example
私の働く会社
It can mean "The company I works for" or "The company I will work for".
When you say
〇〇店が入った雑居ビル
It is clear the sentence only talking about the present, not the future.
In conclusion when you say 〇〇店が入る the sentence itself is ambiguous (but you usually can distinguish according to the context), 〇〇店が入った is not ambiguous it only talking about the present. In other words, there is no practical difference in cases the context is clear.
News program prefer shorter sentences when there is no chance to misunderstand. I think that's why the news program use 入る rather than 入った.