TOPIC: Could you please tell me if they are right?

I read the following paragraph.
We use that and those to describe past activites.
e.g. I'm glad mark got a new car, That old one was so small. ( means we can't use this to replace that in the sentence above)
We can use this and these to describe present activities.
e.g. What do you think of this new organization plan? ( means we can't use that to replace this in the sentence.)
I'm not sure if they are right . Could you please tell me if they are right?

Yes,"that" and "these" can be used to describe past activities.
In the sentence "I'm glad Mark got a new car, That old one was so small",we cannot use "this" to replace "that".
It's also correct that "this" and "there" are used to describe present activities.
We cannot replace "that" with "this" is the sentence "What do you think of this new organization plan?"