BaseViewHolder.kt

abstract class BaseViewHolder<T>(itemView: View) : RecyclerView.ViewHolder(itemView) {
    abstract fun performBind(item :T?)
}

ItemViewHolderPost.kt

class ItemViewHolderPost constructor(val binding: ItemBinding)
    : BaseViewHolder<Model>(binding.root) {
    override fun performBind(item: Model?) {
        //TODO: Bind to view  
    }
}

NativeAdRecyclerAdapter.kt

class WordpressAdapter()
    : PagedListAdapter<Any, BaseViewHolder<Any>>(ITEM_CALLBACK_OBJ) {
    companion object {
        const val POST = 1
        const val NATIVE_AD = 5

        const val NUM_OF_POST_BEFORE_ADS = 4
      
        val ITEM_CALLBACK_OBJ: DiffUtil.ItemCallback<Any> = object : DiffUtil.ItemCallback<Any>() {
            override fun areItemsTheSame(oldItem: Any, newItem: Any): Boolean {
                return if(oldItem is Model &&  newItem is Model){
                    oldItem.date == (newItem.date)
                }else{
                    false
                }

            }

            override fun areContentsTheSame(oldItem: Any, newItem: Any): Boolean {
                return if(oldItem is Model  &&  newItem is Model){
                    (oldItem as Model) == (newItem as Model)
                }else{
                    false
                }
            }
        }
    }

    private val nativeAds = mutableListOf<UnifiedNativeAd>()

    fun addNativeAd(ad:UnifiedNativeAd){
        nativeAds.add(ad)
    }

    override fun getItemViewType(position: Int): Int {
        val nativeAdRows = getNativeAdRows()
       return if(hasNativeAds() && nativeAdRows.contains(position)){
            NATIVE_AD
        }else {
           POST
       }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<Any> {
        return when (viewType) {
            NATIVE_AD -> NativeAdViewHolder(ItemNativeAdBinding.inflate(LayoutInflater.from(parent.context), parent, false)) as BaseViewHolder<Any>
            else -> ItemViewHolderPost(ListviewRowBinding.inflate(LayoutInflater.from(parent.context), parent, false), listener) as BaseViewHolder<Any>
        }
    }

    override fun onBindViewHolder(holder: BaseViewHolder<Any>, position: Int) {
        when (getItemViewType(position)) {
            NATIVE_AD -> {
                val adPosition = position * nativeAds.size / itemCount
                val nativeAd = nativeAds[adPosition]
                holder.performBind(nativeAd)
            }
            else ->  holder.performBind(getItem(position))
        }

    }

    fun onNativeAdLoaded() {
        val rows = getNativeAdRows()
        rows.forEach {
            notifyItemInserted(it)
        }
    }

    private fun hasNativeAds(): Boolean {
        return nativeAds.isNotEmpty()
    }

    private fun getNativeAdRows(): List<Int>{
        val rows = mutableListOf<Int>()
        for (i in 0 .. itemCount){
            if(i != 0 && i % NUM_OF_POST_BEFORE_ADS == 0){
                rows.add(i)
            }
        }
        return rows
    }

}

NativeAdViewHolder.kt

class NativeAdViewHolder (private val binding: ItemNativeAdBinding) :
        BaseViewHolder<UnifiedNativeAd>(binding.root){

    override fun performBind(item: UnifiedNativeAd?) {
       //TODO: Bind 
    }

}

Yes, you're right. It would override some. But can one modify paging 2.0 data after it's been created? I think that's only possible in paging 3.0