Black Lab Games published another dev diary, explaining the upcoming changes in Warhammer 40,000: Battlesector that will have adverse effects on the backbone of Space Marines.
Intercessors, the Primaris equivalents of tactical Space Marines of the Firstborn, proved to be ever-reliable in Warhammer 40,000: Battlesector which made them one of the fan-favourite units, even though they are much more accessible and available from the very start, unlike some of the more exotic and powerful ones. However, an upcoming Battlesector update might take away some of their usefulness even though they are not getting nerfed directly.
The update is going to revamp the way damage is calculated on armour targets when they are hit by low-damage firearms. Therefore, when a beefy Tyranid walks up to a bunch of Emperor's chosen, they will have to rely more on Plasma weaponry to bypass its defences because low-penetration guns will get blocked more often, negating their damage entirely.
It's pretty obvious the Intercessors will get hit by this change, especially if they took the anti-swarm weaponry, but other units will suffer from the new calculation as well. Sidearms will seldom be able to go through thick armour so you would do well to upgrade the Inceptors' guns as soon as possible or the agile unit might not find much use besides clearing swarms of tiny enemies.
When these changes kick in, you might want to rethink your army composition in missions that feature a lot of enemy armour as Hellblasters might become your best shot at overcoming those sturdy carapaces.