According to a study from 1962 there were two people in Oregon who spoke Coos. It is not an unreasonable assumption that in 2007 nobody speaks Coos any more. Suppose that Ishi had some profound things to say; his message was recorded and it was recorded on a wax cylinder in 1911.
So let us consider this situation. Ishi spoke Coos, his language is now extinct and he used the technology of the day and left a recording of his message. We do not speak the language any more and we have problems with technology less than hundred years later. This wax cylinder is owned by the Phoebe Hearst Museum of Anthropology and we might be lucky; there could be a complete set of annotations including translation of Ishi's words. When we are lucky, we can listen to the the Ishi recording 96 years later and have some understanding through the possible annotation; a window is opened in our past.
When Ishi had spoken his message in English, we would consider it to be easier for us to understand it. The message would still be from a different culture, it would still require the same annotations for us to understand it properly. Now Bill who was also living in Oregon, had an as profound message. Suppose Ishi and Bill knew each other, Ishi's background would be Coos, and Bill's background would be Welsh. Our ability to understand their true message would depend on our understanding of that time. Without sufficient understanding of the culture, the profound message of either Bill or Ishi will not reach us. It would be an artefact of a museum, an artefact to be studied.
For Bill and Ishi it might have been of great significance that their profound message was recorded. For Ishi it would be natural to communicate in Coos, it was his language and it is not unlikely that is was only recorded and annotated because it was Coos. Bill's message was not recorded, his English and his message was not considered of similar significance.
Much of what is said and done, is done only for the present moment. My message is written in English because it is the best way for me to convey my message. Many of the messages of Sabine are in Neapolitan when she reaches out to that particular audience. My message is written on Blogger, I do not spend much thought considering its format. If at all, it may be saved for posterity thanks to the effort of the Internet Archive. When people cannot read it, understand it in 100 years time, I do not really mind as they are not my intended audience.
Much of what we do on our Wikis is for our current audience. Our content is transient, its shelf life is limited. We aim to bring information to our public and we to do this now. We provide Free content and when a wealth of content is available in a format like Flash, we should imho provide it because we aim to provide the best possible service now. With the continued development of Gnash, I feel reasonably safe that a future generation will still be able to experience some of what our day and age is about. The stuff that I really enjoyed.. well that is another story.. some people try to preserve it..