As far as I know it definitely helped promote the benefits of the HST and the London commuter services, where clearly the targeted customer was the deep pocketed businessmen (deliberately gendered term, because it was the 80s) with alternative travel means.
This was a nascent sign the corporation was being pivoted to a state where it would see passengers as customers and aim to win their custom via modernising and taking a ruthlessly commercial approach, with a view to one day turning a profit, or at least cross subsidising regional rail.
Sectorisation also seems to have aimed to focus the freight business on either being more innovative and thus competitive as a mode where that applied (parcels, small freight) or simply providing a better service and thus higher fees where BR effectively only had to be better than the customer themselves could arrange via rail (trainload freight).
Privatisation wasn't inevitable. Notably it wasn't the Evil Thatcher but John Major who applied this long standing ideological policy to BR, with things like sectorisation and other planned reforms perhaps persuading Whitehall to take a wait and see approach (busy as they were with far easier and way more lucrative privatisations).
But the sad reality was that for all these changes, the 1992 general was fought to a backdrop of BR subsidy having doubled in just two years, and with the 1980s privatisations by Thatcher having seemingly met their objectives - turning state run loss making monopolies infamous for their poor corner service, into gleaming corporate giants beloved by the stock market (arguably a mirage, but politics is necessarily a short term game).
Major won, and the train set was duly dismantled. It's a long time ago now, so the idea the state of the railways today can be attributed to decisions made thirty years ago, is absurd as arguing the state of BR in the eighties was a result of decisions made in the 50s. In both cases, fault lies in what was being done in the preceding decade (the only realistic planning window for something like a railway).