Is it true that the usage of Appostrophies is not encouraged in US Business English?
No, that's not true at all.
If you mean that we don't use a lot of contractions in formal writing (isn't, didn't, don't), that has a small amount of truth.
I am a business writer and I make my living writing business English, and I use contractions when they sound natural. I omit them only in the most formal types of writing. In articles, brochures, presentations, and of course e-mail, I use them.
(Note the correct spelling.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.