Hi, just wondering, in the grand scheme of things is it possible that in a truck 6.5td sitting for 2 years outside in alaska, that the trans fluid could degrade enough to gunk up the tranny enough to stop it from working right?

Do you mean it was parked, unused, for two years?

Yep, after the lady i got it from hit a moose with it, it sat outside for 2 years unused...

B4 you start it, check the trans fluid for milky color indicating water - anything metallic will 'sweat' as temperatures cross the dewpoint.
You wouldn't want that sludge passing thru the filter, and being liquid, it will pass thru.

Not only that, water dissolves some of the other particulate, allowing it to pass thru the filter.

Best would have been to drop pan, drain the trans b4 starting, with new filter.

Same for all fluids - engine, transfer case, differential.

So far everyone I've opened was well soiled with varinsh like oil and metal dust.

So bear with me guys, But is it safe to assume that if i drove it like that after sitting so long, could all that sediment and varnish clog up the particulate in the filter preventing fluid flow thus not allowing it to shift, or drive right?

i would sat that there is a 99%CHANCE THAT THE FLUID IS FINE but it woulden't hurt to do a trans service as it has been sugested

Codes? It would help to know what DTC's have been stored they could do it.
check and clear them and if problems continue, go through the trouble shoot at the local tranny shop or take it to the lube shop like bowtie does and have them flush it out and put in syn. fluid and a tranny treatment, then expect to drop the pan and change the fluid/filter not long after. At that time you can look at the A and B shift solenoids for gelled oil.