Census Johnston believes Samoa would never have participated in the World Cup without threatening to strike in November.
Experienced prop Johnston scotched rumours he was forced to retire from Test rugby by Toulouse, revealing he had a deal for World Cup release with the French club all along.
Samoa only relented on industrial action at the 11th hour in November, eventually facing England at Twickenham despite disputes over pay and back-room infrastructure.
Johnston confirmed World Rugby brokered new agreements that have revolutionised Samoa's set-up and secured their World Cup participation.
"We do feel vindicated for threatening to strike in November, even though that was an extremely tough position to be in," Johnston told Press Association Sport, ahead of Saturday's World Cup clash with South Africa.
"For guys who play for tier one nations, they're just used to having very solid, very secure systems.
"And we've had years of not being used to what's going on, and that's just a relief and a weight off the boys' shoulders.
"And we can focus on the rugby now, not figuring out whether we're going to get paid.
"We've ended up getting a bit of a pay rise, it's nothing compared to what the tier one nations get, but it's a step forward.
"Everything's changed. We've got a new CEO, we've got a new high performance manager, and I've arrived in the last few weeks and just seen huge changes.
"The organisation of everything has been set, we know what's going on, so we can purely focus on our job on the field.
"Before we were always worried about things not happening for us, and boys were paying for things like physios out of their own pocket.
"World Rugby and the International Players Union (IRUPA) helped us have talks with the union in the months after November.
"In the last month we were able to sign a deal that will hopefully give Samoa a better future.
"It's crucial for the next generation of players, if we want them to choose Samoa over potentially another nation."
England beat Samoa 28-9 at Twickenham on November 22, 2014, at the end of a turbulent and emotionally-charged week where a strike was only averted at the last minute.
Johnston missed out on initial selection for Samoa's 31-man World Cup squad, but revealed he always had a deal with head coach Stephen Betham to be drafted back in if required.
The 34-year-old replaced injured Leicester prop Logovi'i Mulipola in Samoa's ranks on September 9 - after initially retiring from Test rugby in April but reversing that decision in July.
Samoa saw off the United States 25-16 in their opening Pool B match last weekend, and now face a wounded South Africa at Villa Park on Saturday.
Mike Stanley slots in for Tusi Pisi at fly-half, with Johnston taking a seat on the bench - and expecting a Springbok onslaught.
"It's an exciting time, I thought at one stage I wasn't going to make it and I'm just happy to be here," said Johnston.
"It was more to do with timing with the club, when I decided to retire it was something between me and the club. We had to try to arrange good timing too.
"I spoke to Steve about that, and we agreed that if there was an injury he was going to pull me in.
"I never had a two-tier contract that would be one amount for retiring from Test rugby, and less if I continued. All Toulouse asked was for me to make sure I could play the first four games of the new season.
"Once there was an injury, I'd played those games, and so was able to come back into the squad.
"I think my situation was perceived wrongly, but now it's great to be back. It feels like my birthday!
"We always knew South Africa were going to be tough - the only change now is that Japan have gone and made them angry.
"They will be breathing a bit of fire on the weekend now."