Alexban, you need to check with your trainning department to get the real answer.
According to JAR, pilots who don't have 250 PiC hours, required to get full ATPL, can log up to 150 hours of RHS time as PiCUS. The method of logging needs to be put down in OM-D and it has to be acceptable to licencing authority. Almost all aviation authorities are quite happy with logging F/O's PF time as PiCUS, no strings attached. However, some companies decide that their F/O's will not be upgraded soon and refuse to credit them with PiCUS time, in order to keep them less attractive for prospective new employers (most airlines require full ATPL for F/O newjoiners). So check your airline policy.
When you mentioned that your new captains log PiCUS, I thought for a moment that we work for same company, but your type showed me we're not. At my place, this is for cost saving - if you're not logging PiC, then you are on F/O's pay.