A ? for our Excel Guru's and MVPs

Considering that we are under the Microsoft Forum Domain and as a simple
excel user. I need to know what are the guarantee we can obtain from 3rd
party Add Ins or formula building in standard excel program considering the
following.
1. Excel program always upgrade itself..Will the suggested formula building
thru 3rd party suggestions be guaranteed as integral part of any excel
upgrade?
2. If there are formula suggested under this forum that are not covered by
the Help Files samples and Function description, will this microsoft forum
guarantee the CHECKED MARKS and such checked marks will be integral to all
the succeeding microsoft Upgrades. I am not foolish to obtain any suggestion
even they are CHECKED if these suggestions are not explained or distinguished
precisely by microsoft help files considering the risk in the future that I
may not able to use the old MS files, utilizing unexplained formula
structuring by the excel programmers himself or MS Support files.
I hope you can bother to give comments since excel's future is based on the
present.
thanks for any clear and guaranteed reply..