So now we have the 2MB blockchain implemented by Bitcoin classic... what will happen if I will still be using my older mutibit wallet when majority are using this one? will my transactions still work or everyone will have to upgrade in time? thanks!
transactions are never lost.
transactions sit in the memory of every mining pool. so all transactions will get added to blocks.
without complicating the scenarios. the only difference you will see is that your transaction will appear in blocks at different times.
all miners will have the pool of transactions so whether its:
(B)ig blocker that happens to remain at a higher blockheight it will be added to their block.
(s)mall blockers would ignore the (B)ig blockers and make their own blocks as if the transaction has not yet confirmed(due to ignoring(B)). so it would be added to their block too.
and if small blockers gained blockheight. the large blocks would get orphaned and the data would align back to the small blockers. so your transaction will exist.. but the number of confirms will change
the ultimate result would be that if a service you use is relying on large blocker data. then there is a chance that a confirmed transaction can be rejected and then when realigning, may show a different amount of confirmations because its now seeing the data of the small blocks. which also has your transaction, but maybe added at a different time.
EG
lets say the current block was 400,000 and you transmitted a new transaction.
both miners receive the transaction but,
(B)ig blocker added it to 400,001
(s)mall blocker doesnt add it to 400,001 for many reasons (i wont complicate the scenario)
(s)mall blocker added it to 400,002
so 30 minutes after you sent the transaction(at 400,003)..
a service viewing (B) chain will see the transaction has 2 confirmations (because it was added to their chain(B) 2 blocks ago)
a service viewing (s) chain will see the transaction has 1 confirmations (because it was added to their chain(s) 1 blocks ago)
then lets say, that at that same 400,003 (s) got blockheight instead (as a scenario). and so (B) orphans off its bigger blocks and grabs (s) chain as thats the new height.
a service viewing (B) chain will then see the transaction now has 1 confirmations (no longer 2 because the block 400,001 that had your tx in the big block doesnt exist)
a service viewing (s) chain will see the transaction has 1 confirmations because its the same data on both chains due to the height that caused orphans on (B)