If I pre-select a seat within an Economy cabin, prior to a flight, does that in turn reduce the likelihood of receiving an "operational upgrade" to Business at the airport (should

If I pre-select a seat within an Economy cabin, prior to a flight, does that in turn reduce the likelihood of receiving an "operational upgrade" to Business at the airport (should one be available)?

I do understand that op-ups at check-in are generally allocated on a status tier basis (I'm currently QF Platinum), however I have always assumed a specifically pre-reserved seat allocation precludes me from an upgrade... Either explicitly by airline policy, or precluded by human factors (namely check-in staff having more work to change the booking).

Further to this, are the staff at premium counters & lounges more prone to proactively switch you to a higher class, if an op-up is available?

I'm not sure on Qantas' policy, or Virgin Australia's for that matter, but over the past two months I've received 3 op ups from Y to J on VA. (I'm a VA Plat)

All were on Saver tickets and for each flight I had pre-selected a seat. These are the only 3 op-ups' I've had and I've been a Plat for a few years. I'm not sure if VA's internal policy has changed to start doing this more for high tier pax or if they have just increased the practice of overbooking Y. 

My main point is with VA at least the factor of a pre-selected seat didn't seem to affect my luck in any way at all. I doubt QF would be much different from that perspective, would mostly be to do with status and if Y is overbooked. 

Thanks for taking a crack at answering mate, def not your typical "how many guests in lounge" sort of easy AusBT question haha. Appreciate your info, yes VA and QF likely to have similar policies, so that does give me some satisfaction that op ups are likely to disregard pre-allocated seating. Much appreciated!