Yes, evening reception a party, drinks, dancing, buffet or hog roast etc. I also don't think it's an insult to be only invited to the evening do.
Restrictions on venue capacities and ridiculous prices charged for a formal sit down wedding breakfast dictate that most people cannot possibly invite every work colleague, friends other than the closest ones and distant relatives to their actual wedding, but may want everyone to get together to celebrate, so an evening only invite makes sense.
Mumsnet is weird about weddings in general and I think there are some people who are impossible to please.
An invite is just as likely to offend as no invite
There is almost certainly going to be something 'wrong' with the venue, catering, day or time etc
You are supposed to pretend that it's not the done thing to take a gift to a wedding but at the same time it is the height of rudeness to go without taking one.
I think what you are 'supposed' to do is send out your invites with no mention of gifts, leaving guests having to chase relatives of the bride and groom, who they may not know and have no contact details for, to ask for the wedding list.
The list must be a carefully chosen list of household items at a range of prices that the couple may or may not want or need, but while it is fine to buy someone a toaster, it is always extremely rude to ask for a contribution towards a honeymoon or simply cash.
If anyone does that, then you either shouldn't go to their wedding or buy them a passive aggressive gift to show that you know better, such as a photo frame, because even if the couple say 'no gifts' you can't respect their wishes and not take one.
The above only applies to UK weddings where the couple are of UK origin. If it is in Ireland, you must give the couple hundreds of euros or not go at all, even if they're close relatives or your best friend.